360 questions

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SGGDuster

SGGDuster

Dreaming of Burnt Rubber
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My dad owns a 1987 Dodge 360 custom pickup, I don't really know much about it except that it has a 360 in it and a four speed manual with a low "granny gear" for tearing houses off their foundations. I am basically wondering (given the engine is in good shape) what would make it a suitable street engine for my 74 Duster. I have a 318, but we all know more power is always good, so if anybody could give me an opinion on how to make the 360 a worthy street engine, if it is even worth it, I have no idea.

My dad's been trying to sell the truck, but nobody wants to pay a decent amount of money for it, so I might be able to buy the engine or steal it or something.

Thanks
 
any V8 will like the standard parts like a set of headers a nice 4barrel aluminum intake manifold and a good ignitionsysem to make some more power;) then it starts to cost some more money... more cubes are always better, but i think many people swap there 318´s when they dont need to 318 can be built to make power and behave like a 340....but i live in a a country where it is harder to find a 340 or 360...
 
How handy are you? How much $ do you have? That motor may be one rebuild away from being a real winner! A 360 is a fine motor even if it is not in race trim. All things being equal a 340 will beat the tar out of it but you don't NEED a fire breathing HEMI to have a good time. Since it was mounted in a truck the heads, intake etc were designed for truck duty so it may not be ideally suited for muscle car service; that need not deter you, though. Having a 360 around to trick-out while you use the 318 (another fine engine in its own right) could be a good project or maybe just drop it in. I'm not sure about the K-member and suspension upgrades you may need, but I say go for it.

Keep'em comming -LY
 
LY, All things being equal a 360 is a 340 with an addtional 20 cubic inches of displacement so the power advantage goes to the 360.

Granted 360's as delivered from the factory were not in as high a state of tune as a 340 but if you are rebuilding a 360 it's a no brainer to build one that makes more power than a 340 that is built to the same level of tune.
 
Pembroke, MA? Did you go to Silver Lake? I had that math class too, Mr Randall sure knew how to deliver that one. Thank you, you clarify my point very well regarding the 360s. To my knowleged the 340s were only deployed for performance; although my 73 is realistically putting down around 275 HP these days which is anemic compared to some of the 360s I have seen not to mention the 416s. Do they still have the cruise night over at the Wall Mart parking lot in N. Plymouth? Man do I miss that place!
 
I graduated from Whitman-Hanson but my kids graduated from Silver Lake, which by the way no longer includes Pembroke. The Class of 05 was the first for the new Pembroke H.S.

No cruise at Wal-Mart in N.Plymouth, for that matter, there is no Wal-Mart in N.Plymouth anymore. Wal-Mart moved up off the "new Rt44" near the Cherry St Industrial Park.

There is a cruise on Fridays at the Wal-Mart in Halifax. This one has grown to be as big as N.Plymouth was at it's peak with 300+ cars on a Friday night. Bourne Tech H.S. cruise on Tuesdays is still the biggest with 700-1000 cars.

FWIW, I estimate the 360 in my 68 Barracuda at 375HP.
 
Lone Yankee said:
All things being equal a 340 will beat the tar out of it but you don't NEED a fire breathing HEMI to have a good time. Since it was mounted in a truck the heads, intake etc were designed for truck duty so it may not be ideally suited for muscle car service; that need not deter you, though. Having a 360 around to trick-out while you use the 318 (another fine engine in its own right) could be a good project or maybe just drop it in. I'm not sure about the K-member and suspension upgrades you may need, but I say go for it.

Keep'em comming -LY
Click to expand...

I strongly disagree here. Like said, right after you, the 360 is very very similar to a 340. The differences are larger mains. This takes up more HP, but on a street ride, you'll never know it.
The bore is 4.00 , slightly smaller, but the stroke is 3.58 vs. 3.31. This equals more torque. The longer stroke also will limit RPM up top but the longer stroke has a earlier peak in HP.
Longer stroke engines may not make as much HP as a shorter stroke engine, but it is very very close in max output.

The 360's advantage besides being a little cheaper is bigger torque and earlier peak HP is a cheaper block or engine to obtain than the 340.
Also, think of it as 20 free cubes. All torque.

A 9.0-1 (min.) comp engine and decent flowing heads like a set of Edelbrocks and a mild cam like a simple off the shelf Comp/Isky...of 280-480 will knock out 380 HP no problem with small tube headers.

Weather or not the engine came from a truck or not doesn't mean squat. It IS the same engine no matter what it came from. The only things that could be different are cam, valve springs, timing chain (Double roller) and other non-HP related items. The differences are for longevity in a harde working envioment.
The 340 & 360 share engine mounts as the 273-318 share engine mounts. Get new ones reguardless on the new build. Cheap ins against failure from years of abuse and service.
No K-member changes needed or suspention upgrades unless you want it. The 360 and 318 are very very close in total weight.
Once the headers and aluminum are on, there basicly identical in weight.

Almost forgot, the 360 is externally balanced as well as the 1 year only extranl balance 340 (1973) All other small block engines are internaly balanced. So there is a balancer up front issue and flywheel/torque converter balance issue at the back.

How much power is it your looking for?
 
dgc333: Halifax Wall-Mart!? Man am I ever out of it! If I find myself over by 106/58 on a Friday, I'll have a look-see, thanks.

RumbleFish: Thank you for posting, that is very good information. I completely forgot about the internal/external balancing issues. I was always under the impression that "truck 360s" were tuned to run at lower RPMs and made poor muscle car engines. Thank you for the correction. That is one of the things I like about this place, I learn something new every day! That would also help to explain, I suspect, why you can by 360 crates but not 340s. I do have a question, then. I was always told that the early 340’s had an edge on account of their forged cranks which allowed them to wind-up over 7k RPM. Is that still an important factor versus their new 360 cousins or does the newer tech with the greater displacement more than make up for that? I greatly value your input. Aint' this stuff fun?

-LY
 
sure those shortstroke 340´s like high rpm, but a 7000+rpm 340 is realy on the edge of what is a street engine its something that is realy fun when it screams at high rpm but its not even close to bee as torqey as a nicely built 360 for street use...i know i amdriving a street 340 with 7500+ rpm capacity on the street and its on the edge, cant realy say that it is a great street engine its more like a detuned race engine and if i would just be intresed in a engine for crusing an/or some stoplightaction i would build a 360 insted..
 
This is quite a wealth of information coming my way, thanks!

As far as power goes, I don't have a specific goal. Basically, I have a potentially free 360 block (depending on what dad ends up doing with the truck) and I'd be willing to give it a thorough (patient!) rebuild while I run the 318. Basically, I was thinking pistons, heads, intake off my 318 (RPM Air-Gap), and small tube headers off the 318, and of course a new bumpstick. It'd be awesome to be able to say that I have 400 horses under my hood (though I like torque more), but I don't want to rob a bank to be able to say that.

The engine mounts have me a bit confused. Would the ones on my car now work or did I understand that 340s and 360s used different mounts? If so, that's just a swapping deal, right? No kind of fabrication?

Thanks again, this has been really helpful!
 
The ears on the drivers side of the 340/360 block are about 1/2" closer together than on the 273/318 block.

I ordered what I thought was a 360 mount for the drivers side of my 360 and it turned out to be for the 318. I just made up a spacer with a stack of washers to fill the gap on between the ear and the mount on the rear bolt. So, Yes, you can use your 318 mounts if you don't have any heart ache with using a longer bolt and a spacer.
 
Gotta luv free with anything mopar these days if your dad will give it up? Parts are easy to order when it comes time to do your build. If you end up doing the build try to save up some loot and slap on some aluminum heads. I had a very similar situation fall into my lap 2 months ago when my uncle said a 440 he had in a c-body that sat too long. I tore it down and had a magnaflux done and no cracks. So maybe sometime next year I can afford to sink some money into building it for my dart. Incidentally, anyone know how much a 440 is going for these days?
 
a good 360 is easy to build. Build your self the best short block you can afford.
Zero decked flat top piston work perfect with closed chambered heads, go moderate on the cam for a street car and use a good dual plane intake. Remember its easier to change heads and camshafts later then pistons if you need more power.
 
AdamR said:
a good 360 is easy to build. Build your self the best short block you can afford.
Zero decked flat top piston work perfect with closed chambered heads, go moderate on the cam for a street car and use a good dual plane intake. Remember its easier to change heads and camshafts later then pistons if you need more power.
Click to expand...


what he said ;)

I skimped on the heads for now in favor of going .030 over on my 360. KB flat tops and a zero deck.

I went with a Crane 278 Cam, new springs <of course> and a RPM manifold <soon to go to an air gap>

I have no problems at all with my 360, and feel she's a solid motor. I can drive it with all the confedence in the world.. I was at the same place you were, build the 318 or go 360.... I went with the free power to start with.

The only problem I have is people saying "360's didn't come in these!"... i just ignore them ;)
 
I say so what, besides it's my car that needed a motor and this is what I F$%^*ing put in it so go Srtyu gi;eh io ehigh buei ; ohihiohio7$^795* k 09e!!!!!!!
And thats the way it is. :love8:
 
the only problems with 360's in stock trim was the lack of compression. They simply weren't build for power- more like reliability, in stock trim you won't notice alot of difference in power(more use of fuel though) unless your 318 is really wore out. Build the 360 with some flat tops to get the compression up and find some earlier 360 heads (J heads would be perfect but getting harder to find) and learn to port a little. Just cleaning up the castings (gasket matching and polishing- not to smooth on the intake though!) will help- Mopars castings weren't that great in the 70's. Or if you really want to go crazy open them up to 2.02 intakes- alot of work though, better if someone who has done it before guides you along. For a cam Comps Extreme Energy line is awesome!- especially for a street car great low end and they don't stop pulling. Lunatis new Voodo line is good too but a little more aggresive meaning you'll have to spend more cake on the top end(springs/valves) Just remember whatever cam you go with don't go to big you'll kill your bottom end and thats where you want your street motor to work the best.
 
I'm facing the same problem about putting a 360 in a 74 Duster with a 318. Is there a mount to buy that would correct the problem with the driver's side motor mount? I guess I can do the fix mentioned above with the washers and spacers. But I really wanted an actual mount that I could buy w/o having to fab anything. Everything I have found has been to put a 340/360 in a 67-72 A-body. Are the mounts different on the 73+ A-Bodies from the 72 and earlier a-bodies?
 
I think you can just buy a 360 motor mount for a 73-76 Dart/Duster as far as I know just the mount width is different, they were talking about re-using mounts right guys? I'm almost possitive that the K-frames are the same- Back me up here guys?
 
The 73 and up A-body K-member uses a completely different design for the motor mounts. Where the 72 older used a flat biscuit with a bolt coming out of each side the 73 up is what is called a spool mount. There are two ears on each side of the k-member with a slot in the top. The motor mount fits down between these and is clamped in by a long bolt that goes from the front to the rear of the car. The rubber isolation a rubber spool (very much like a control arm bushing) the OD is pressed into the bracket that bolts to the engine and the bolt that clamps to the ears on the k-member goes through the ID.

It's a more secure design and will not allow the engine to flop around if the rubber fails like the biscuit mount.

I had a part number for the drivers side mount which was different from the 318 mount but turned out to be the same, some places listed the same number for both the 318 and 360 mounts. Don't know if I got a missed marked box or what but since the spacer thing was so simple I just went that route
 
the 273/318 left hadn bracket is different from the 340/360 left side. You can buy them new off ebag for about $30. That's where I got mine. After '72, the spool mounts are used..That's the one with the integral rubber isolator. The '67-72 all use the seperate isolator, and the K frames are different for the two different bracket setups.
 
I've heard that early to mid 70s 318 heads on a solidly built 360 short block will make great power as well. The smaller intake runners means more velocity. Anyone else heard this?
 
It would probably build a good amount of torque but its going to limit the top end.
 
Really think so? I saw this combo posted somewhere??

360 .030 and stock parts in the bottom end.
318 1.78 Intake 1.60 exhaust (gasket matched bowl blended)
.473/.491 with 272/276 @ .050 from comp. cams
M-1 intake and 1 7/8 hedders
1030 alky carb
chrome box ign. from mopar
587 HP @ 6500
489 ft.lbs. torque @ 5000

"The reason the engine works so well is because of the small heads and valves. The reason we did this is because the camshaft is way way too big and there wouldn't be any signal for the fuel to be pulled out, so by using the small heads the engine thinks that the cam is really smaller because the velocity is soo good, and it fills the engine like a better set of heads and a smaller cam, in this way less is better"
:study:

How much money is that in headwork? Although the 270 dur. at .050 is way bigger than my planned 230 dur at .050 but I'm interested in learning more about using the heads for a street motor.

-Alex
 
The 360 is a fine engine for any car. It was built for performance, but performance you can use..That's low speed torque. I would do a solid performance rebuild on the shortblock. KB (or similar) pistons at 0 deck, re-done factory rods w/ARP bolts, blueprint the block, and internally balance it. Wiht the right top end and cam, you have a base that can make 275-450hp reliably, on pump gas. For heads, a good set of performance iron heads will cost around $900 to get done, and done right. That's mild porting/gasket matching, new SS valves, chambers cc'd, the works. A real compression of 9.5:1 with factory heads, the right cam, and you have a solid 425tq and 400hp on tap..Reliably, that will last daily driving for years, and run on mid grade pump gas. With an upgrade later to Edelbrocks, or similar AL heads, you can get more compression, more power, on super unleaded. That's what I'd do. Around here, it would cost $3K or so for a long block, a little more with the oil pan for the 360 (not the same as 318)

On the mount thing..Chances are, the catalog is wrong DC..not your fault. Contact Schumacher Creative services for unbreakable correct mounts for a 360/340 in a later Dart. The earlier biscuit versions are easy to get off Ebag, or several suppliers for $20-40. You may be able to get the right mount, by having a good parts guy (not the typical P/C typer at Auto Zone) look in a book (real printed ones even..) and get the part for a '73 340 Dart. I'm not positive, but many passenger cars with 360s will probably use the same mount, like a 360 Monaco, diplomat, Fury, Barracuda/Challenger, etc. for '73 to the 80s.
 
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