LA 360 Engine refresh?

[John Collins]

I have ‘73 Dart Sport with an LA 360/904 that was built by someone 15 years ago and I don’t know anything about the specifics of the build, but here’s what I do know. It has a 360 block casting number 4006830-360-9, 3769974 head – 1975-1976 1.88/1.60 valves, Mancini Racing Adjustable Rocker Arm Set, 904 transmission, TTI headers, an Edlebrock Performer 318/360 intake manifold, a 9635 625 CFM Carter AFB competition series 4 barrel carb, MSD ignition and digital 6a ignition Blaster 2 coil and distributor, rebuilt 60A Alternator, a 26 inch radiator. Not installed, but already purchased... 8 3/4 rear with 489 case helical sure grip with 3.23 gears, ESPO 6 leaf springs with new shackles and bushings, Hotchkis front sway bar and a front end rebuild kit from Mancini.

What I’m mostly looking to do is clean up the engine, replace gaskets, check for any foulness and improve compression a bit if I can. I know there’s a long list of things I can replace while I’m at it, but there’s only 29k on the engine, so I’m hoping for good luck when I open it up. My first and only thought was too port the heads and possibly the intake manifold for a performance upgrade and possibly replace the Carburetor(looks as well for the carb). It was suggested that I buy cheaper Summit Heads though. I’d go that route if I can find a pair for cheap. I’m not looking for crazy horse power, but more is better. If I clean up and sell my current heads will it be similar in cost to buying “cheaper” heads after you factor in the machining costs? I’m uncertain as to what Cam I currently have as well. Thank in advance for any insight or suggestions!

 

[John Collins]

I really don’t want to pull the engine. I also plan on changing the water pump and timing chain.

 

[dano]

So what don't you like about the existing engine combo?

 

[John Collins]

I don’t mind it. It runs well. There’s a slow slow oil leak up top somewhere and I’m cleaning up the engine bay, so I figured I give it a refresh and learn a few things in the process. I’m very much a novice and bought this car as a project to keep me sane while being a stay at home dad(******* Covid). I’ve been watching a ton of videos, reading tons of online articles and how to’s and I’m inspired to take the jump and improve this ride myself. Also, since I don’t know anything about the engine build and I’m curious to know what I have. I’m also changing the 7 1/4 open rear to an 8 3/4 sure grip 3.23 and have been told that I may want to change my cam.

 

[dano]

I hear you there, been home since March with my wife and two boys. The up side is I got a lot work done to my car.

All the work your going to do is with the engine installed in the car? If so, that's tough but doable. Is this your first time with building an engine/car or is this something you've done before?

So help us out, what do you want out of your 360 and how do you intend to use it, (i.e nice street cruiser only, drag race only, got handling street car, etc)? This will help us a lot in helping you. I will say mystery rebuilds are difficult to modify because you don't know whats inside in the terms of static compression, valve springs, cam shaft, etc. From you description some one built a mild performance 360. Have you looked into the tune as in initial and total timing, carb settings, read plugs? Sometimes you'll find that a mild engine can really be woken up with a good tune.

 

[John Collins]

I hear you there, been home since March with my wife and two boys. The up side is I got a lot work done to my car.

All the work your going to do is with the engine installed in the car? If so, that's tough but doable. Is this your first time with building an engine/car or is this something you've done before?

So help us out, what do you want out of your 360 and how do you intend to use it, (i.e nice street cruiser only, drag race only, got handling street car, etc)? This will help us a lot in helping you. I will say mystery rebuilds are difficult to modify because you don't know whats inside in the terms of static compression, valve springs, cam shaft, etc. From you description some one built a mild performance 360. Have you looked into the tune as in initial and total timing, carb settings, read plugs? Sometimes you'll find that a mild engine can really be woken up with a good tune.

I’m looking for just a strong in the city driver with a bit extra on it for the weekends. I plan on selling it in the future and just want something fun, but not crazy. I’ve helped friends build their engines in my youth, but nothing for myself where I was the primary person holding the wrench and that was 20 years ago. So, yeah I’m definitely a novice, but I’m not afraid to get in their and get overwhelmed. Lol.

I tuned it myself, but without a timing light, messed with carb a bit and put new E3 spark plugs in. It runs pretty nice, but my curiosity and the leak are making me want to open it up. I’m going in knowing that I’ll be challenged daily, but I’m here to try and learn what I can before I start making mistakes and hopefully absorb some good advice.

Thank you!

 

[Dartswinger70]

What you can do without pulling the engine is ,intake valve cover and timing cover gaskets. The Oil pan? yeah maybe but I'd rather have it in a stand for that. For all the labor jacking the engine to get the pan out etc. I dunno I never liked attempting it in the car. Plus you can be more meticulous in how you install the oil pan gasket etc. Do the rear main seal if it needs it. when you have the valve covers off ,check rocker shaft bolt torque etc. If you have adjustable rockers ajust them

 

[John Collins]

What you can do without pulling the engine is ,intake valve cover and timing cover gaskets. The Oil pan? yeah maybe but I'd rather have it in a stand for that. For all the labor jacking the engine to get the pan out etc. I dunno I never liked attempting it in the car. Plus you can be more meticulous in how you install the oil pan gasket etc. Do the rear main seal if it needs it. when you have the valve covers off ,check rocker shaft bolt torque etc. If you have adjustable rockers ajust them

My main issue with pulling the engine is that I’m solo and fear of actually doing it is a major road block, second is if have to rent or buy a cherry picker and third is space. Potentially I can use my neighbors space while I’m doing this. With that said, it sounds like I should pull the engine. I also wanted to clean up the headers, but was going to pass on it because I’m afraid of pulling the engine. Lol. What’s your advice on pulling it solo, or should I phone a friend?

 

[Dartswinger70]

My main issue with pulling the engine is that I’m solo and fear of actually doing it is a major road block, second is if have to rent or buy a cherry picker and third is space. Potentially I can use my neighbors space while I’m doing this. With that said, it sounds like I should pull the engine. I also wanted to clean up the headers, but was going to pass on it because I’m afraid of pulling the engine. Lol. What’s your advice on pulling it solo, or should I phone a friend?

You can pull it solo just use the right tools a carb lift plate helps or an engine tilter etc. I have used a chain bolted diagonally, don't pull the hood unless you absolutely have to. I know most guys pull the hood first and put it on the roof, not always necessary. Having two guys there helps as it is two sets of eyes, i have dinged the paint on my fender well doing it myself. If that is not a concern go for it alone. Also use common sense ,if it isn't coming out ,you missed a bolt somewhere, don't yank on it ,stop and find the bolt. Things like that, just take your time. Be prepared for a mess, anti freeze will spill etc, get kitty litter for oil dry. Also once you clear the car, lower the engine on the cherry picker before rolling the picker. This lowers the center of gravity and prevents the picker from tipping over etc. Just common sense, the engine is heavy so keep feet clear etc.

 

[dano]

My main issue with pulling the engine is that I’m solo and fear of actually doing it is a major road block, second is if have to rent or buy a cherry picker and third is space. Potentially I can use my neighbors space while I’m doing this. With that said, it sounds like I should pull the engine. I also wanted to clean up the headers, but was going to pass on it because I’m afraid of pulling the engine. Lol. What’s your advice on pulling it solo, or should I phone a friend?

The easiest way is to drop the engine, K frame and lower control arms/spindles (leave the calipers) out the bottom. Trans too if you want.

 

[John Collins]

I saw a video on that a while back... They used a floor jack slightly raised to support the weight of engine/ K-frame assembly, unbolted everything and removed all the lines that were connected and dropped it on dollies, then jacked the car up with a cherry picker. Seems easier to manage alone, rather than trying to guide it in from above. I need to do my homework on that one though... It seems simple in theory, but I’m sure there’s pitfalls waiting for me.

 

[dano]

I saw a video on that a while back... They used a floor jack slightly raised to support the weight of engine/ K-frame assembly, unbolted everything and removed all the lines that were connected and dropped it on dollies, then jacked the car up with a cherry picker. Seems easier to manage alone, rather than trying to guide it in from above. I need to do my homework on that one though... It seems simple in theory, but I’m sure there’s pitfalls waiting for me.

It's how I do mine. There are several things to disconnect but worth it. It keeps from beating the crap out of the engine bay and so much easier if you have headers. You do need to get the car high enough to roll it out. Its really helpful if you intend to do suspension work at the same time like bushings, torsion bars, etc. I would still have a second hand to do it preferably with a good set of eyes and beer holding experience.

 

[John Collins]

It's how I do mine. There are several things to disconnect but worth it. It keeps from beating the crap out of the engine bay and so much easier if you have headers. You do need to get the car high enough to roll it out. Its really helpful if you intend to do suspension work at the same time like bushings, torsion bars, etc. I would still have a second hand to do it preferably with a good set of eyes and beer holding experience.

I’m going to rebuild the front end for sure, it’s toast and also putting a front sway bar. Would a month be long enough of a build time to get the engine work and suspension done? Considering, I have all my parts and ducks in a row. Seems plenty to me, but I imagine I’ll get caught up on a few things. I only ask because I want to talk to my neighbor about using his garage space.

 

[dano]

I’m going to rebuild the front end for sure, it’s toast and also putting a front sway bar. Would a month be long enough of a build time to get the engine work and suspension done? Considering, I have all my parts and ducks in a row. Seems plenty to me, but I imagine I’ll get caught up on a few things. I only ask because I want to talk to my neighbor about using his garage space.

It depends on how much time you have free to work on it, tools, etc. I think the simplest you keep it the better. If I may interject some advice, keep the engine together as much as possible unless there is something wrong. Fix the leaks and any other easy low hanging fruit. If I may ask, why do you want to replace the timing chain? Have you done a compression test?

 

[John Collins]

It depends on how much time you have free to work on it, tools, etc. I think the simplest you keep it the better. If I may interject some advice, keep the engine together as much as possible unless there is something wrong. Fix the leaks and any other easy low hanging fruit. If I may ask, why do you want to replace the timing chain? Have you done a compression test?

Copy. Pretty much every thread I’ve read suggests replacing it if you’re “refreshing” an engine. It’s probably just fine. I’m just a little eager to get my hands dirty. What do you consider “low hanging”? Would you leave the heads alone? I have not done a compression test yet. That would be a good start. I never done one, but will look into it more. I know you have to unplug the distributor and fuel pump and test through the plug hole, but that’s it. Lol. I need to research it more. Thank you!

 

[Dartswinger70]

All of the above is true. i have never dropped one out the bottom but would consider it if I had a lift to raise the car up away from the engine K frame assembly. As far as "easier" I don't know if there is such a thing, I for one don't like working off a creeper, when I was younger, yes, now no. I would cherry pick it out the top, leaving the trans in, but I have experience doing this and I don't figure its difficult. very little time on a creeper. Now with a lift, its a non issue, you put the car up, pull all bottom bolts, lower down, do the top etc. With headers, there is an order of operations, I remember lowering one side in with the engine as i lowered it down, I seen to think it was the right side, that took tow people one to hold the header, one to lower the cherry picker. manifolds, they come out the top. The exhaust studs go into the water jackets ,the ones on the very end. if you break one or pull one and there is antifreeze, that's normal. i remember being young and dumb drilling out a broken exhaust stud, anti freeze came out, i figured Id ruined the head, went to the yard and got another one. this was back when they were a dime a dozen. One thing I have learned is, old cars are fun but not necessarily "easier" to work on than new ones. mechanics in the early 70s still complained

 

[dano]

Copy. Pretty much every thread I’ve read suggests replacing it if you’re “refreshing” an engine. It’s probably just fine. I’m just a little eager to get my hands dirty. What do you consider “low hanging”? Would you leave the heads alone? I have not done a compression test yet. That would be a good start. I never done one, but will look into it more. I know you have to unplug the distributor and fuel pump and test through the plug hole, but that’s it. Lol. I need to research it more. Thank you!

Low hanging to me is and leaking gaskets, core plugs, or the like if they need it.

Compression test you do with the engine warmed up, all plugs out and WOT on the carb. Leave the distributor plug alone and just disconnect the coil wire that goes to the cap. Probably can leave the fuel alone, the floats and seats will keep the bowls from filling as you turn it over 4-6 times. Write down the results and post. Honestly with 30k and it runs good I would leave it alone.

Changing things can become a slippery slope like converter size and adequate springs for a cam change and are the push rods correct length still. Heads can change compression ratio, which means you may need to change cams or degree the one you have to set the dynamic compression ratio and are your rocker providing the correct geometry on the valve tip and enter push rod length again. Now is you intake and carb up to the task of changes? I know it sounds daunting but It can and is done, just know what your getting into with a change.

Then when you have a hot motor can the car handle it? Brakes, suspension, etc all pivotal to change and it is a package.

If it were me with what you have I would fix the leaks, review the current tune and see if it needs help and drive it. If I wanted more power i would find another core 360 or 5.9 (or buy a crate engine because building an engine isn't cheap anymore) and build a new engine and plan when supporting parts it need to be successful.

 

[John Collins]

Low hanging to me is and leaking gaskets, core plugs, or the like if they need it.

Compression test you do with the engine warmed up, all plugs out and WOT on the carb. Leave the distributor plug alone and just disconnect the coil wire that goes to the cap. Probably can leave the fuel alone, the floats and seats will keep the bowls from filling as you turn it over 4-6 times. Write down the results and post. Honestly with 30k and it runs good I would leave it alone.

Changing things can become a slippery slope like converter size and adequate springs for a cam change and are the push rods correct length still. Heads can change compression ratio, which means you may need to change cams or degree the one you have to set the dynamic compression ratio and are your rocker providing the correct geometry on the valve tip and enter push rod length again. Now is you intake and carb up to the task of changes? I know it sounds daunting but It can and is done, just know what your getting into with a change.

Then when you have a hot motor can the car handle it? Brakes, suspension, etc all pivotal to change and it is a package.

If it were me with what you have I would fix the leaks, review the current tune and see if it needs help and drive it. If I wanted more power i would find another core 360 or 5.9 (or buy a crate engine because building an engine isn't cheap anymore) and build a new engine and plan when supporting parts it need to be successful.

I’m going to take your advice and only fix the leaking gaskets. I changed the spark plugs a couple days ago. Is there a compression test kit you’d suggest? Your advice on buying another core and slowly building/planning/accumulating all the necessary parts is exactly what my buddy who’s built too many cars to count keeps telling me. “Just start driving the car and stop messing with it” is pretty much what he tells me when I call him for advice. Lol. Thank you sir!! I appreciate the intel.

 

[67dartgtgo]

I'd follow dano's advice and concentrate on other things first if it's a decent runner now. After fixing the oil leak, sounds like an easy fix, I'd do the rearend and springs first and drive it for a while, tuning to get it at it's best. With only 29k on it I'd leave it in the engine bay, leave the heads on it and upgrade the cam first. Heads are pricey no matter what you do. You can do the heads with the engine in the bay but it's a little more work considering header bolt access on the driver side but doable. I wouldn't touch the timing chain unless I were upgrading the cam, with such low mileage. Your buddy sounds pretty smart...lol. Good luck.

 

[John Collins]

I'd follow dano's advice and concentrate on other things first if it's a decent runner now. After fixing the oil leak, sounds like an easy fix, I'd do the rearend and springs first and drive it for a while, tuning to get it at it's best. With only 29k on it I'd leave it in the engine bay, leave the heads on it and upgrade the cam first. Heads are pricey no matter what you do. You can do the heads with the engine in the bay but it's a little more work considering header bolt access on the driver side but doable. I wouldn't touch the timing chain unless I were upgrading the cam, with such low mileage. Your buddy sounds pretty smart...lol. Good luck.

I get caught up the idea of doing something and just go for it. This definitely a time to pump the brakes and just enjoy it for a while. Thank you!

 

[aaronk785]

Your at the right place. I’ve learned a ton on this site in the last 7 years.

 

[John Collins]

Your at the right place. I’ve learned a ton on this site in the last 7 years.

Agreed. This site has helped me tremendously. Before each project, I come here first and search the archives... It’s been my most important tool so far. I’m only three months in... lol. I have a long road ahead of me, but I’m looking forward to it.

 

[dano]

I get caught up the idea of doing something and just go for it. This definitely a time to pump the brakes and just enjoy it for a while. Thank you!

And you know sometimes its OK to dive in. I've known a lot of project where people tore them apart going to do something and they sat, lost interest and get sold for nothing or rot away. After tearing my GTS apart in 1997 and just now driving it 2 weeks ago I can attest to that. Body work and paint, multiple engine issues, me changing my mind on parts, redoing my own work or someone I paid to do its work, it can get long in the tooth and expensive and it's easy to give up or burn out on it.

 

[John Collins]

And you know sometimes its OK to dive in. I've known a lot of project where people tore them apart going to do something and they sat, lost interest and get sold for nothing or rot away. After tearing my GTS apart in 1997 and just now driving it 2 weeks ago I can attest to that. Body work and paint, multiple engine issues, me changing my mind on parts, redoing my own work or someone I paid to do its work, it can get long in the tooth and expensive and it's easy to give up or burn out on it.

That’s a long road! I sold my other car and this will be my daily driver... More like occasional driver. I’m a not driving much during the week and my wife has a Q5, so we use that for longer trips. This inevitably will be a weekend cruiser with the family and to go to Sunday meetups, until I sell it or trade up to build the next one. I don’t need more than it has, to be honest... I guess I’m just bored while waiting for parts for my front and rear suspension to come in. Thank you for talking me out of something I had no business diving into yet!

 

[dano]

That’s a long road! I sold my other car and this will be my daily driver... More like occasional driver. I’m a not driving much during the week and my wife has a Q5, so we use that for longer trips. This inevitably will be a weekend cruiser with the family and to go to Sunday meetups, until I sell it or trade up to build the next one. I don’t need more than it has, to be honest... I guess I’m just bored while waiting for parts for my front and rear suspension to come in. Thank you for talking me out of something I had no business diving into yet!

No problem, I find myself in the same boat. I have a 2019 Cherokee in the drive way I bought last year as my commuter for a daily 27 mile, 1 way commute. Since March I've put maybe 1k miles on it and now I need a truck to do home projects and didn't buy a truck in the first place due to my commute. Consider yourself lucky to get parts too, lots of shortages and supply chain is pretty dried up.