273/ 2 barrel camshaft options

[GHOST RUSTERS]

Hello forabodies community and thank you for welcoming me and my family!

(Warning: I am NEW to ANY Internet forums/ community and I tend to babel. I don’t know when to shut up so please feel free to correct me with keeping it short and sweet or over sharing)

I do have a detailed heartfelt story explaining the backstory to my individual background and the importance of the Barracuda that I am working on if anyone is interested in reading, not sure if this is the correct outlet for any storytelling, but the offer is on the table. (This car has been a part of my fathers life since he was 7 years old, the car “disappeared” for many years and after 10+ years of VERY difficult searching and legal matters, I was able to find and rescue the car in 2018. This is a family project with my two daughters in getting it safe and road worthy to surprise my dad when the time is right)

Currently, the 273 block and heads are at a local machine shop for a very light clean up and inspection for cracks or any potential build concerns.

(A quick blueprint: The engine is original, was rebuilt in 1985 with .040 bore, .020 on rods, .020 on mains (can still see clean, clear crosshatch on the cylinders and rod caps) I have the original build badge that was on the block for this information if that’s helpful. The car was driven for a few years after the rebuild. The trans reverse went out and the car was parked for 20+ years, until I found it)

As of right now I would like to keep it as factory/ basic as financially possibly because this is THE engine that my dad learned and worked on in is developing years. We are trying to avoid any unnecessary machine work, a refresh if you will, clean up and reassemble)

I disassembled the engine (I did take measurements first. I was able to get it to run briefly beforehand. It had oil pressure and compression was roughly 120 across the board, but sounded ugly in the lower end)

I was recently told by the machine shop that the cam “got hot” and is “trash” and here is my cry for help in joining forabodiesonly. The cam does show “pitting” please see pictures.

What are my options in either “repairing” the existing camshaft or replacing it without having to take out a loan. I have not been able to find another original 273 cam. Is there a direct swap out for just a cam or will it have to include replacing everything, pushrods, lifters, rockers and so on? What’s the risk of just reusing the cam and lifters as is?

I understand and respect that quality isn’t cheap. But this isn’t going to Pomona for drags and I won’t be looking for Milner to race for pinks, I’ll leave that up to Harrison Ford. It will be driven to take the family to get ice cream on the weekends and the occasional cruise for my dad.

Any information and or experience is greatly appreciated with help regarding the original camshaft or any other challenges this may present. What can be done or should be done? I have had very little luck on eBay or Craigslist in finding another original cam for solid lifters. If I need to share more pictures please let me know. I am willing and capable of receiving constructive criticism.

(If it helps, I’m in my late 30s, I’m a mechanic in the gas/oil fields in the Midwest, my mechanical experience came from working on chainsaws in a logging shop as a child into automotive machanic work on cars and trucks from the 50s, 60s and 70s and modern as a well… if I’m being honest to help put myself in your crosshairs I’m gonna say that I enjoy watching The Waltons, Vice Grip Garage and Uncle Tony’s Garage if that helps in introducing myself.

Again I apologize for the babbling and the long story. My daughters and I are excited to be a part of this community and we look forward to your participation. (I am a working man with a schedule so if I don’t respond or communicate clearly while I figure this out in chatting, forgive me while I learn the ropes. Thanks again and Bad Fish for Life!

 

[73Charger318]

I'm about to rebuild a 273 4 bbl in a 1965 Cuda, and this is the cam that many here have recommended.

Racing Cam [390144] - $360.00 : ISKY Racing Cams, Do It Right

ISKY Racing Cams Racing Cam [390144] - Racing Cam Solid Valve Lift Int/Ext. 0.425 Valve Lash Hot Int/Ext. 0.015 ADV Duration Int/Ext. 260 0.050 Duration Int/Ext. 216 Lobe Center 108

iskycams.com

 

[junkyardhero]

I disassembled the engine (I did take measurements first. I was able to get it to run briefly beforehand. It had oil pressure and compression was roughly 120 across the board, but sounded ugly in the lower end)

I was recently told by the machine shop that the cam “got hot” and is “trash” and here is my cry for help in joining forabodiesonly. The cam does show “pitting” please see pictures.

What are my options in either “repairing” the existing camshaft or replacing it without having to take out a loan. I have not been able to find another original 273 cam. Is there a direct swap out for just a cam or will it have to include replacing everything, pushrods, lifters, rockers and so on? What’s the risk of just reusing the cam and lifters as is?

okay, so it sounds like you're having the machine shop handle most of the motor, or at least the bottom end. are you doing the rest of the build out or just sourcing a cam and they're gonna put it all together?

that cam is trash, so forget about it or repairing it. the lifters look garbage too, although they might be salvaged with a reface. which leads me to the thought of how do the pushrods and rockers look?

other questions:
>do you want to retain solid lifters
>are you going to leave it stock 2bbl
>do you care about performance or is just stock fine enough

there are many cams that you can swap in and retain at least your rockers. you may or may not need push rods. either way you're going to need a cam.

 

[toolmanmike]

I'm about to rebuild a 273 4 bbl in a 1965 Cuda, and this is the cam that many here have recommended.

Racing Cam [390144] - $360.00 : ISKY Racing Cams, Do It Right

ISKY Racing Cams Racing Cam [390144] - Racing Cam Solid Valve Lift Int/Ext. 0.425 Valve Lash Hot Int/Ext. 0.015 ADV Duration Int/Ext. 260 0.050 Duration Int/Ext. 216 Lobe Center 108

iskycams.com

Isky E4. A great cam mild solid lifter cam for a stock or slightly modified 273. 2 or 4 barrel. It has just a little chop, idles smoothly at 650 or so and pulls strong to 5500 or more.

 

[Dana67Dart]

I do have a detailed heartfelt story explaining the backstory to my individual background and the importance of the Barracuda that I am working on if anyone is interested in reading, not sure if this is the correct outlet for any storytelling, but the offer is on the table

Great back story!

I personally love the back stories more than the cars themselves.

Welcome aboard! Love the fact that you are having your daughters assist. They will have great memories later in life after the get done this king your the stupidest person in the world

My back story is similar. I was 4 when the family went to pickup my dad's first and only new car.

I grew up in the car, and learned to drive in it.

My dad drove it for 25 years as his daily driver, 325,000 miles later after his passing im keeping it alive!

As for CAM.

You can download, free, your cars Factory Service Manual from mymopar.com.

In the FSM are the cam specs and you can use that to help if a replacement.

The members who have suggestions will be great reference too.

Not sure what you know about 273s but there are 2. 64-65 had unique intake manifold bolts due to the heads. The block and bottom end is the same as 66-69

66-69 heads will bolt on the 64-65 block and allow for more intake options.

If you think you might want to increase performance in the future AND you need to replace the heads it might be a good way to go to change the heads and intake to 66-69.

There is nothing wrong with the 64-65 heads or intake.

Good luck to you and have fun with your daughters and your dad. Don't take a minute for granted!

 

[AJ/FormS]

Just so you know;
I'd run those lifters on any half-decent used 318 cam.
Meaning;
I already have, and it ran for miles and miles and miles, using the old normal-zinc oil.
Heck, If I had a good used 360 cam, I'd run that.
Meaning, I already Have.
And, if you don't like that Idea, you can just convert the valve gear to run hydros.
Meaning, I already have done that too.
Furthermore, I have run uglier lobes than the one in your post.
Just so you know.

But Here's the thing;
Back in those years, decades ago, I was not afraid to go back in at a later date and backtrack. To me, it was just time, (of which, being a young unmarried man, I had lots of) cuz I always had another old cam laying around, and lifters, and etc.
It just never happened.
Your results may vary.

And finally, If you're gonna keep that engine at 8/1 Scr, You need to keep the Intake Closing Angle, at or very near to what the factory had. If it gets to be too much later, you will be thinking of installing a higher-stall convertor, and/or gears soon following.
Just so you know.

 

[GHOST RUSTERS]

okay, so it sounds like you're having the machine shop handle most of the motor, or at least the bottom end. are you doing the rest of the build out or just sourcing a cam and they're gonna put it all together?

that cam is trash, so forget about it or repairing it. the lifters look garbage too, although they might be salvaged with a reface. which leads me to the thought of how do the pushrods and rockers look?

other questions:
>do you want to retain solid lifters
>are you going to leave it stock 2bbl
>do you care about performance or is just stock fine enough

there are many cams that you can swap in and retain at least your rockers. you may or may not need push rods. either way you're going to need a cam.

Hi and thanks for the feedback! The machine shop, as of now, is set to clean and inspect the block and the heads to determine what can and can’t be reused. Once we determine the block doesn’t have any cracks or major defects, we’ll need to find a replacement cam and related components, they will install the cam bearings and the cam. After that, I will be reassembling everything else at home with the family as a winter time project.

As for the condition of the rocker arms, those are still on the heads at the machine shop so I don’t have current accurate pictures, the push rods look to be in good shape and everything disassembled with ease, no bends or binding (I am mechanically inclined but I am not a machinist and I have no shame in admitting that I don’t know what I don’t know if that’s fair)

I don’t have an answer for you regarding keeping solid lifters. The goal was and or is to “refresh” the engine, clean everything and reassemble everything as it was, until we discovered the camshaft condition. Having said that, I am not particular either way, whichever camshaft would install as easily and as cost effectively as possible without replacing other major related components. What cam can take a stock 273s place and what else has to be done and or changed in doing so?

As for the 2 barrel, it is important to me to keep the engine as close to original as possible because as I mentioned that’s THE engine that my dad learned to wrench on, but As Dana67Dart mentioned, the options between heads and manifolds does present other possibilities. Im familiar with the difference in the angled head bolts but I had no idea the carb and manifold could be changed. I’m not against any option there really. My dad will be happy to have it move under its own power regardless.

I came here for education and wisdom and in just 24hrs of my post I’m already in school and I’m grateful for you and everyone else for chiming in and sharing, truly.

Performance wise, the goal is to make it safe first and foremost and road worthy, turn the key and go for my dad’s sake. I’m not looking to smoke the tires. Maybe enough exhaust tone to get some appreciation at the car shows in Deadwood someday but really just enough to enjoy cruising the badlands with the family or letting my dad take the girls out for ice cream.

I hope some of that answers your inquiries. Basically, I’m on a shoestring budget to get my dad’s 273 up and running, I’m reusing ans many existing parts as possible, and I need a cam that the shop can install and try for a plug and play. The rest is up to me and my girls in learning as we go and hopefully creating some memories good enough to look back on in the photo albums one day.

Thanks so much for your time and input!

I did find a few older pictures of the heads and you can kinda see the rockers and pushrods and some of the pistons I’ve cleaned up, if that helps.

 

[GHOST RUSTERS]

I'm about to rebuild a 273 4 bbl in a 1965 Cuda, and this is the cam that many here have recommended.

http://[URL]https://iskycams.com/shop/index.php?main_page=product_info&cPath=127&products_id=608

[/URL]

Hey thanks! I’ll read into that and see what’s involved. Is it as simple as just the cam or would these change out lifters, pushrods and rockers as well do you know? Good thoughts for your build and thank you!

 

[GHOST RUSTERS]

Great back story!

I personally love the back stories more than the cars themselves.

Welcome aboard! Love the fact that you are having your daughters assist. They will have great memories later in life after the get done this king your the stupidest person in the world

My back story is similar. I was 4 when the family went to pickup my dad's first and only new car.

I grew up in the car, and learned to drive in it.

My dad drove it for 25 years as his daily driver, 325,000 miles later after his passing im keeping it alive!

As for CAM.

You can download, free, your cars Factory Service Manual from mymopar.com.

In the FSM are the cam specs and you can use that to help if a replacement.

The members who have suggestions will be great reference too.

Not sure what you know about 273s but there are 2. 64-65 had unique intake manifold bolts due to the heads. The block and bottom end is the same as 66-69

66-69 heads will bolt on the 64-65 block and allow for more intake options.

If you think you might want to increase performance in the future AND you need to replace the heads it might be a good way to go to change the heads and intake to 66-69.

There is nothing wrong with the 64-65 heads or intake.

Good luck to you and have fun with your daughters and your dad. Don't take a minute for granted!

Hey thanks so much for the feedback! 325k! That’s some respectable preservation! Keeping metal on the road I love it! What a cool legacy to have in the family story. And I did not know about the mymopar that could prove to be very helpful. I extremely thankful that you cleared up the confusion on the changes in the 273 blocks, heads, and manifolds issue and that is comething Ive thought about, being able to go from the 2 barrel to a 4 with a different manifold and heads. BUT there in lies the scarcity of finding any other donor 273 parts especially where I am, and I imagine the cost grows quickly when going bigger and badder, and I have no shame admitting that this a shoestring budget build. Clean it, assemble it, run it.
I sure do appreciate the info and I think I’ll read some more into the head/manifold options if this cam issue brings it all to a stop. Thanks!

 

[GHOST RUSTERS]

Just so you know;
I'd run those lifters on any half-decent used 318 cam.
Meaning;
I already have, and it ran for miles and miles and miles, using the old normal-zinc oil.
Heck, If I had a good used 360 cam, I'd run that.
Meaning, I already Have.
And, if you don't like that Idea, you can just convert the valve gear to run hydros.
Meaning, I already have done that too.
Furthermore, I have run uglier lobes than the one in your post.
Just so you know.

But Here's the thing;
Back in those years, decades ago, I was not afraid to go back in at a later date and backtrack. To me, it was just time, (of which, being a young unmarried man, I had lots of) cuz I always had another old cam laying around, and lifters, and etc.
It just never happened.
Your results may vary.

And finally, If you're gonna keep that engine at 8/1 Scr, You need to keep the Intake Closing Angle, at or very near to what the factory had. If it gets to be too much later, you will be thinking of installing a higher-stall convertor, and/or gears soon following.
Just so you know.

“Just so you know” and “I already have…” never did I think my eyes would light up with hope reading those words haha. Thanks so much for taking the time to read my post and comment! I like that positive motivation!

Curious though, you mention having ran a cam with worse lobes than mine… are you confirming and or denying that it could be maybe should should not do don’t haha to run my cam as is? This was suggested to me from another source once before saying to get it cleaned up, no grind just remove the surface rust and run it with the same lifters and add a zinc additive in the oil. My first thoughts wouldn’t this just continue to break down quickly and send shrapnel through the system into the block and bearings and so on?

The isky racing cam seems to be tried and true from what I am reading. Again, I am inexperienced in certain portions, what else would need to be changed or altered to be able to run that cam? Springs, pushrods, lifters?

Thank you for the information and the clever grammar truly appreciate the attention to detail.

 

[junkyardhero]

probably one of the biggest considerations is do you want to keep the cam as solid lifter?

that in and unto itself doesn't really dictate anything except for your cam and rocker gear, it's just a matter of personal taste and whether you want to keep it *exactly* as your pops had it. and the task of finding a solid cam that is a decent grind and not $$'s.

the budget seems to be steering the ship, so in that manner i'd throw down with a melling SPD-20 cam and melling hydraulic lifters. this is basically a stock replacement stuff that is affordable and will work with the stock adjustable rocker arms and likely pushrods. you could go a little more aggressive on the cam, but you're hemmed in by cost considerations and the stock 2bbl intake & carb that you're likely going with-- but upgrade to a 4bbl intake/carb and then more cam choices are available.

you have lots of moving parts at this stage of the game. i'd sit tight and wait till the all clear comes back on the heads & rockers and then make my decisions from there. if you need heads that changes the direction of the build considerably.

 

[Dana67Dart]

manifolds issue and that is comething Ive thought about, being able to go from the 2 barrel to a 4 with a different manifold

I'm pretty sure there was a stock 64-65 4 BBL in intake

 

[4spdragtop]

Welcome aboard, and thanks for the story! Beautiful kids too!
A Disclaimer, I am NO ENGINE BUILDER, but I can put them together, and from experience a low compression 2bl 273 can be overcammed VERY EASILY. That is exactly what I did and regretted it. That cam may be able to be reground? I believe Racer Brown Cams is known for that? Same with getting those lifters refaced. Any new stuff is a gamble, and I would hate to see you go thru the agony of having to redo it again.
Good luck, just a couple more options for you.

 

[eekvonzipper]

Welcome aboard, and thanks for the story! Beautiful kids too!
A Disclaimer, I am NO ENGINE BUILDER, but I can put them together, and from experience a low compression 2bl 273 can be overcammed VERY EASILY. That is exactly what I did and regretted it. That cam may be able to be reground? I believe Racer Brown Cams is known for that? Same with getting those lifters refaced. Any new stuff is a gamble, and I would hate to see you go thru the agony of having to redo it again.
Good luck, just a couple more options for you.

I Agree! Racer Brown Reground My Cam right in between a Stock 2bbl and a Commando w/ .405 lift I believe...
Woke My 273 Right Up!

 

[4spdragtop]

Nice! What pistons in yours? 2bl or domed?

I Agree! Racer Brown Reground My Cam right in between a Stock 2bbl and a Commando w/ .405 lift I believe...
Woke My 273 Right Up!

View attachment 1716285791

View attachment 1716285792

 

[Bewy]

The cam in post #14 is quite small, may not have have as much 'oomph' as the original cam. That is because solid lifter cams with 018" lash are equivalent to about a hyd cam 9* shorter at 050. So equivalent to a 189 @ 050 hyd cam; equivalent meaning, gives equivalent performance.
Also, using a re-ground cam might lead to lash adjustment problems because the base circle of the cam is reduced in size; consequently, lifters sit lower & rocker adjustment screw needs to be screwed in further to get the correct lash. Ok if there is enough thread on the adjuster.....

I agree with others that the Isky E-4 cam is best. Isky cams are good. If you do not want lifter/lobe failure, have your old lifters re-faced; they look in reasonable condition. Do not buy new lifters, they fail.
NEVER, EVER USE USED LIFTERS ON A NEW CAM....NO MATTER HOW GOOD THEY LOOK.

 

[eekvonzipper]

Nice! What pistons in yours? 2bl or domed?

2bbl Pistons... it's a Commando Clone from the Cam up.

 

[GHOST RUSTERS]

Welcome aboard, and thanks for the story! Beautiful kids too!
A Disclaimer, I am NO ENGINE BUILDER, but I can put them together, and from experience a low compression 2bl 273 can be overcammed VERY EASILY. That is exactly what I did and regretted it. That cam may be able to be reground? I believe Racer Brown Cams is known for that? Same with getting those lifters refaced. Any new stuff is a gamble, and I would hate to see you go thru the agony of having to redo it again.
Good luck, just a couple more options for you.

Hello and thank you for the response. I appreciate the knowledge and sorry to hear about your experience. That’s exactly why I am here, I don’t know what I don’t know, it seems that any aftermarket cam may greatly affect or upset the cam related components I’m working with. Until I hear from the machine shop I’m hopeful for a refrains and resurface with what I have, if not I’m reading more on weather the isky option would “over cam” the existing setup. Thanks again for sharing!

 

[GHOST RUSTERS]

2bbl Pistons... it's a Commando Clone from the Cam up.

View attachment 1716285795

Wow! That’s gorgeous! What a beautiful build! How does a commando “clone” differ from a standard 2 barrel? As I’m still learning about my dad’s 273 and the small block mopars in general, I did not know there was a difference in the pistons, curious what I’m set with. I’m including some pictures of the pistons that I pulled out and have been slowly cleaning for inspection. The machine shop said they felt confident in me reusing the entire assemblies, piston, rod, wrist pins and even rings. Thanks again for sharing!

 

[toolmanmike]

Hello and thank you for the response. I appreciate the knowledge and sorry to hear about your experience. That’s exactly why I am here, I don’t know what I don’t know, it seems that any aftermarket cam may greatly affect or upset the cam related components I’m working with. Until I hear from the machine shop I’m hopeful for a refrains and resurface with what I have, if not I’m reading more on weather the isky option would “over cam” the existing setup. Thanks again for sharing!

The Isky E4 is fine for the lower compression 2 barrel. Here's the 273 cam specs and the E 4 specs. A little extra duration and lift won't hurt a thing. There have been dozens of members here that have installed a E4 with a 2 barrel. The small carb will just limit your upper rpm.
Basic 273 cam specs:

1965 180 hp 2 barrel .395 /.405 lift 240°/ 240° duration
1965 235 hp 4 barrel .415 /.425 lift 248°/ 248° duration
1966 235 hp 4 barrel .420 /.430 lift 248°/ 248° duration
Isky E4 .425/.425 lift 260°/260° duration 216° @ .050

Here's a link to my 273 build just below.

 

[Jim Kueneman]

Hello and thank you for the response. I appreciate the knowledge and sorry to hear about your experience. That’s exactly why I am here, I don’t know what I don’t know, it seems that any aftermarket cam may greatly affect or upset the cam related components I’m working with. Until I hear from the machine shop I’m hopeful for a refrains and resurface with what I have, if not I’m reading more on weather the isky option would “over cam” the existing setup. Thanks again for sharing!

The Isky cam above is not over "over cam" for your engine with a 216 @ 0.050" duration. The definition of "over cammed" that I use is when someone put in a cam without thinking about the rest of the engine. The cam is the first thing you pick and that choice defines the personality and usage of the engine. _Everything_ after this is an output that is calculated based on the cam selected. The thing that I have seen most people get wrong is thinking a cam swap will give them instant magical awesome engine. When you make that cam selection you _must_ have the correct compression for that cam or will kill low end torque. The cam may offer a more high end breathing but because that longer duration cam has more overlap the cranking and dynamic compression goes down. The main factors in low RPM (I mean RPM that you use when drive normally on the street) are cylinder pressure and cubic inches. Bigger cam without increasing your compression will make low end torque worse and sometimes way worse, i.e. over cammed. This is really true on 225 slants (typically 7.5:1 from the factory) and later 318's (typically only a little better). Have your machine shop calculate/measure what the compression ratio will be when they are done then decide what cam to use. I personally would get one ground at Oregon Cams that matches well with your engine (most commercial cams will have to much LCA for stock heads). The heads don't flow well and have small valves so the other thing (based on David Vizards methods) is you want a low LCA (like 108 and with that engine maybe 106) like that ISKY cam is, though you need to be careful if you have too much duration that will give you more overlap and the same things start to occur. Need to know 3 things before you can really get a good cam recommendation

1) What are you trying to improve, low end torque/power or make the engine run better at high RPMs
2) What is your static compression and depending on the first answer this may need to change.
3) Are you doing anything to the heads to make the flow better.

Jim

 

[AJ/FormS]

Just so you know;
a 318 is just the equivalent of a big-bore 318.
So, anything off a 318 , except the piston assemblies, will swap over.
Except the 65 and older heads, sorta need the matching bolt-angle intake. So then;
if you intend to put a 4bbl on it, at some time in the future, IMO, I would start with 67>69 closed chamber heads. If you go with the open chambers and a bigger cam, then the cylinder pressure will fall way too low to be fun.

as for cams;
> on a low compression engine, with an automatic, if you install a lopey cam, you will be sorry, see Post 13, above.
> if you change the cam, I highly recommend to tighten up the LSA(Lobe Separation Angle) in an effort to keep the cylinder pressure up.
> IIRC, the factory gasket was 020 thick, with an appropriately-sized borehole. Those are no longer available, off-the-shelf.. the closest available is 028, and the bore-hole is huge. the new gasket is thus 6.3 compared to about 3.5cc/atock.
This one single change will drop a true 8/1Scr 273 to 7.76 and the pressure is expected to drop to 130, from 136psi. It may not sound like much, but that is the same as installing a cam of 8* more intake duration, which is more than two cam sizes bigger. Bad trade-off.
Closing up the LSA from the factory 112* to 108, with no other changes, on the 7.76SCR engine, is predicted to jump the pressure back up, to 133 Good Deal. and the bonus is better fuel-economy. Now, if you advance this cam to in at 102, this will reduce your Powerstroke back to what you now have, but increase your pressure to 134, over the factory, 129(with the 028 gasket). This is another good deal.
The point I am trying to make is this;
the factory 2bbl cylinder pressure is already extremely low. and it's only gonna get lower after the gasket swap. That's bad. Adding a bigger cam with a later-closing intake event, is gonna drop the pressure even lower.
If your engine needs pistons anyway, and you need a cam
now is the time to pump the compression ratio up, and neatly get around the problems.

As an example, building to a true 9.5 Scr, will allow you to slide a cam in there of about 10 degree later Ica(intake Closing Angle) and the pressure might jump to 161psi. Excellent deal.
Ten degrees is about equal to 4 sizes, going from a 112Lsa to a 108. That's a lot.
and, on a 108LSA, the compression /power degrees end up about the same as you have now, But the overlap jumps to 46 from 28. If you put headers on that, those extra 18* will make a nice little power bulge starting in the midrange. and the pressure increase will make the bottom-end feel about 22% stronger.
Again, the point is this, careful selection of parts at this stage, can make or break the combo.

Putting that same bigger cam into a 7.75 Scr engine is predicted to lower the pressure to 117psi, and the engine will feel about 15% LESS powerful, on the bottom, as it does when stock.
That's a bad trade! This will require a much higher stall convertor, and likely, a deeper rear gear, just to get moving as it once did.
and/but
46* of overlap is about what the 340s had, so, not much of a lope to it, but maybe enough to satisfy your hunger, lol.
--------------------------------

Oh and to answer your question about the cam lobes falling into the pan,
"My first thoughts wouldn’t this just continue to break down quickly and send shrapnel through the system into the block and bearings and so on?"
yes, that is a possibility. In my case, I was willing to take that chance.
The post you are referencing, was about what I did.
As stated, "your results may vary".
-----------------------------------------
Several decades later, I did lose a cam that way.
However, I run very little preload on my hydraulic lifters, and the ticking began almost right after an oilchange. This was back in about 2004 when the oil companies took the zinc out of the oil, and failed to send me a memo.
Anyway , I figured it out pretty quick, slammed a new cam into it, changed the oil and filter again, added a bunch of supplement, and hoped for the best.
The following winter, I took the engine down, cleaned it out, made some compression/spring changes, and slammed it all back together.
Back then, my car was a DD, so every fall, I took the 360 out for freshening, and swapped in a 318 for the winter; sometimes with an automatic, and sometimes with a manual, sometimes with an overdrive, whatever I was planning to run the following summer. and I changed the rear end ratios around pretty regularly as well. By 2005 or 2006, my kids had all grown up and moved away, so I bought another DD, and the 360 has been under the hood ever since........ with no more cam-trouble.

 

[Jim Kueneman]

The Isky E4 is fine for the lower compression 2 barrel. Here's the 273 cam specs and the E 4 specs. A little extra duration and lift won't hurt a thing. There have been dozens of members here that have installed a E4 with a 2 barrel. The small carb will just limit your upper rpm.
Basic 273 cam specs:

1965 180 hp 2 barrel .395 /.405 lift 240°/ 240° duration
1965 235 hp 4 barrel .415 /.425 lift 248°/ 248° duration
1966 235 hp 4 barrel .420 /.430 lift 248°/ 248° duration
Isky E4 .425/.425 lift 260°/260° duration 216° @ .050

Here's a link to my 273 build just below.

I have struggled with this for a years.. does anyone really know how Chrysler measured duration for a fact? Back then there was no real standard.

 

[toolmanmike]

I have struggled with this for a years.. does anyone really know how Chrysler measured duration for a fact? Back then there was no real standard.

No @.050 specs for sure.

 

[Jim Kueneman]

Just so you know;
a 318 is just the equivalent of a big-bore 318.
So, anything off a 318 , except the piston assemblies, will swap over.
Except the 65 and older heads, sorta need the matching bolt-angle intake. So then;
if you intend to put a 4bbl on it, at some time in the future, IMO, I would start with 67>69 closed chamber heads. If you go with the open chambers and a bigger cam, then the cylinder pressure will fall way too low to be fun.

as for cams;
> on a low compression engine, with an automatic, if you install a lopey cam, you will be sorry, see Post 13, above.
> if you change the cam, I highly recommend to tighten up the LSA(Lobe Separation Angle) in an effort to keep the cylinder pressure up.
> IIRC, the factory gasket was 020 thick, with an appropriately-sized borehole. Those are no longer available, off-the-shelf.. the closest available is 028, and the bore-hole is huge. the new gasket is thus 6.3 compared to about 3.5cc/atock.
This one single change will drop a true 8/1Scr 273 to 7.76 and the pressure is expected to drop to 130, from 136psi. It may not sound like much, but that is the same as installing a cam of 8* more intake duration, which is more than two cam sizes bigger. Bad trade-off.
Closing up the LSA from the factory 112* to 108, with no other changes, on the 7.76SCR engine, is predicted to jump the pressure back up, to 133 Good Deal. and the bonus is better fuel-economy. Now, if you advance this cam to in at 102, this will reduce your Powerstroke back to what you now have, but increase your pressure to 134, over the factory, 129(with the 028 gasket). This is another good deal.
The point I am trying to make is this;
the factory 2bbl cylinder pressure is already extremely low. and it's only gonna get lower after the gasket swap. That's bad. Adding a bigger cam with a later-closing intake event, is gonna drop the pressure even lower.
If your engine needs pistons anyway, and you need a cam
now is the time to pump the compression ratio up, and neatly get around the problems.

As an example, building to a true 9.5 Scr, will allow you to slide a cam in there of about 10 degree later Ica(intake Closing Angle) and the pressure might jump to 161psi. Excellent deal.
Ten degrees is about equal to 4 sizes, going from a 112Lsa to a 108. That's a lot.
and, on a 108LSA, the compression /power degrees end up about the same as you have now, But the overlap jumps to 46 from 28. If you put headers on that, those extra 18* will make a nice little power bulge starting in the midrange. and the pressure increase will make the bottom-end feel about 22% stronger.
Again, the point is this, careful selection of parts at this stage, can make or break the combo.

Putting that same bigger cam into a 7.75 Scr engine is predicted to lower the pressure to 117psi, and the engine will feel about 15% LESS powerful, on the bottom, as it does when stock.
That's a bad trade! This will require a much higher stall convertor, and likely, a deeper rear gear, just to get moving as it once did.
and/but
46* of overlap is about what the 340s had, so, not much of a lope to it, but maybe enough to satisfy your hunger, lol.

Oh and to answer your question about the cam lobes falling into the pan, yes, that is a possibility. In my case, I was willing to take that chance.
The post you are referencing, was about what I did.
As stated, your results may vary.
"My first thoughts wouldn’t this just continue to break down quickly and send shrapnel through the system into the block and bearings and so on?"

Several decades later, I did lose a cam that way.
However, I run very little preload on my hydraulic lifters, and the ticking began almost right after an oilchange. This was back in about 2004 when the oil companies took the zinc out of the oil, and failed to send me a memo.
Anyway , I figured it out pretty quick, slammed a new cam into it, changed the oil and filter again, added a bunch of supplement, and hoped for the best.
The following winter, I took the engine down, cleaned it out, made some compression/spring changes, and slammed it all back together.
Back then, my car was a DD, so every fall, I took the 360 out for freshening, and swapped in a 318 for the winter; sometimes with an automatic, and sometimes with a manual, sometimes with an overdrive, whatever I was planning to run the following summer. and I changed the rear end ratios around pretty regularly as well. By 2005 or 2006, my kids had all grown up and moved away, so I bought another DD, and the 360 has been under the hood ever since........ with no more cam-trouble.

Haha.... we said the same thing at almost the same time ;)