Best Year for Mopar 360 LA Engines

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cidVicious

cidVicious

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Hi Gents,

I'll be looking to install a stock 360 in my 72' Duster at some point and was wondering if any of you can talk about the differences (advantages/disadvantages) between 360s built in various years and what I should look for. For example, if I have a choice between a stock rebuilt 1974 year 360 or a 1976 360, would the later year be preferred? If so, why or why not?

I want to keep this forum somewhat focused, so lets keep the discussion focused on the pre-magnum years.

Thanks,
 
Those two 360's are basically identical if they are 2 barrel motors. If you want to build a performance one then a 1971 360 block would be the best block to use. If you want a stock performance one then try to find a 4 barrel version 360. The Warlock/Lil Red Express motors are probably the highest output stock 360.
 
First 360 LA's were built in 71, so you are talking from 71 up to about 1991 or so, I think. This spans a long time obviously.

From 71 to about 76 or so - the 360's were supposed to have used the same casting for the cylinder walls as a 340 - meaning thicker = stronger = better. Later models are supposed to use thinner cylinder walls. I've heard enough about these differences to question the validity of these claims. My preference would be 75 or older (older the better). Ive seen magazine articles about so called thin wall castings from the late 70's, which when checked were as good a piece as the older castings and vice versa, so its a crap shoot. Core shift is the main issue with thicker walled blocks with even or biased core shift towards the thrust side of the cylinders prefered.

Heads on an earlier 360 (71-72) would be the same casting as a 340 - a "J" casting. J's are supposed to be 99% the same as the "famous" 340 X castings, just add 2.02 intake valves and you are there. I would probably not bother with the older iron heads and just go for some eddies or a magnum conversion.

If it were me and I had the choice of building a motor or buying one already built - I'd check the condition of both pieces very carefully. Do you know the owner of the motor, was the work done to your expectations, was it done by a reputable shop ? For a builder (core type) - What is the condition of the block - good, core, junk ? needing everything ? You also need to ask yourself what you want from the motor, race, street, a little of both ? How fast and in what car will it be put in. The questions become diverse when you start looking at these factors.

This should get you started.
 
66dartgt said:
Heads on an earlier 360 (71-72) would be the same casting as a 340 - a "J" casting. J's are supposed to be 99% the same as the "famous" 340 X castings, just add 2.02 intake valves and you are there. I would probably not bother with the older iron heads and just go for some eddies or a magnum conversion.
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FWIW, all 340/360 heads have the same port size/shape and chamber design until the 308's arrived on the seen in the late 80's and then the magnum heads in the 90's. The only difference in the early 340's is they had 2.02" intake valves. So which head you have is not of concern unless they are 308' or magnums.

2.02 valves in a low compression 360 is not a good choice. The choice between motors should be made based on which is better shape.
 
I am with every one about the year model blocks. 75 or older. That is what I used or tried to use when building a strong high out put motor. But if you are wanting a stock set up any motor will do. If you are going for a all stock motor I would think about going with a Magnum motor. Just keep an eye on the heads. Some of the early Magnum heads had a tendancy to crack. Other than that they were a great motor.
 
cidVicious
I want to keep this forum somewhat focused, so lets keep the discussion focused on the pre-magnum years.
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Any particular reason? Just wondering. BJS has a point about a newer motor. Allthough I myself have lots of LA parts hanging around doing nothing, for now.

The note of a "Lil Red" motor is interesting. Keep in mind the E-58, 4bbl 360 engines are said to have the 340 cam as well as double roller timing chain & a windage tray. I have one on a stand, but have not gotten it apart yet. This would make a great start. What it really needs is just a head milling for a little compression. Though headers would help a bit in breathing.

I have noticed, only in a chiltons and such, that the 2bbl. engines listed @ 8.5-1 and 4bbl. engines @ 8.0-1. I really never opened one up and measured. Has anyone out there done so?

DGC
FWIW, all 340/360 heads have the same port size/shape and chamber design until the 308's arrived on the seen in the late 80's
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The later smog heads are a bit different, No? They didn't seem to port out as well ethier.
 
Thanks everyone,

I'm looking at putting a 360 into a 72' Duster that currently has a slant six. I'm not planning on racing it, I just want to have a nice get-up-and-go street car. I'm not a stickler on keeping the car all original, so going with a 360 in a 72' isn't going to upset me; however, I know it will probably bother some of you guys who like to KEEP IT REAL.

Any tips on what I should expect to pay for a stock rebuilt 360 long block that comes with cylinder heads attached and valve train installed (valve covers, timing cover, intake manifold and oil pan not included)?

Here's a little more detail: This long block has new valves, valve springs, valve keepers, push rods, rocker arms, fulcrums, lifters, camshaft, timing chain (belt), timing gears, valve guides (diamond honed), three angle seats, cam, rod and main bearings, pistons, piston rings, rod bushings, gaskets and oil pump. Cylinder block, cylinder heads, crankshaft and connecting rods are cleaned and shot peened and magnafluxed for cracks. All bolt holes are tapped. Cylinder block is bored to each piston and diamond honed to 18RMS finish. All oil galleys are hand brushed with white cleaning brushes and cylinders are hand cleaned with cleaning solution and white towels. Cylinder heads have each valve guide diamond honed, seats are three angle. After assembly, heads are vacuum checked for valve seating. Crankshaft is ground and polished to 12RMS. Each oil galley is hand brushed with a white cleaning brush. All connecting rods are honed.

Cheers,
 
Sounds like a well put together motor. I wouldn't see any problems with it as a matter of what they say was done to it. I would check on the reputation of the builder (s). If it is a chevy guy he probably put it together with a 3/8 drive ratchet and no torque settings. You can get away with that on a chevy for a little while but not on our motors.
 
Rumblefish from what I have read on the history of the "Express" the Lil Red Express motor is the same as the E-58 360. I was going to mention that motor but could not remember the E-58 part.
 
rumblefish360 said:
cidVicious
DGC

The later smog heads are a bit different, No? They didn't seem to port out as well ethier.
Click to expand...

The only real difference is the the air injector ports.
 
There ya go 340mopar. E-58.
i keep forgetting the 318's E-** number.

Thanks DGC. I seem to remember Steve D saying something about the ports. I coulld be mistaken i guess.

Cid-V, camshafts cam be a fickle thing. If your keeping your current 3.23 gears, it would be IMO, that a cam in excess of 218 - 220 duration is a bit much. Even more so with a stock converter. I suggest a split duration cam to aid in breathing with stock or mildly preped heads. Comp cams extremr cams work very well with headers.,
 
318 = E48
The later model 360 smog heads (injection ports) I have seen on 4 bbl 318's have smaller intake ports to match the head ports. If you look at an engine gasket kit they have two sets of intake gaskets. 1 - 318 and 1 - 360. The 318 gasket matches the 360 smoger 4 bbl intake.
 
Cid - This sounds like a remanned engine you are looking at, the problem with these is they are generic motors which are fine for normal passenger car use, but not really performance oriented. Pricing on these is usually set by the reman outfit, unless someone is selling privately or someone is going out of business. Take a look at Jasper's website for some ideas.

I would tear it down just on general principles and check the bearing clearances. While apart swap the cam if its a 2bbl stocker to at least a 340 stock cam, put stock hi perf valve springs on it, and a double row roller chain on. While in there check your compression ratio. You might find its in the low 8 high 7 range. At that point you could shave the heads to gain CR or just leave it and run the thing.

Let us know what you decide to do.
 
I know it's been a while, but I ended up picking up an inexpensive 1974 360 2bbl with 727 trans that came out of a 1975 Dodge Motorhome. I'm in the process of cleaning it up, adding some old headers, replacing the oil pan, etc. and I'm looking at upgrading to a 4bbl carb. It's been fun researching and looking around for all this stuff and I'm glad I now have something to work on.

Thanks for all of the help and I'll let you guys know when the motor is in the car and on the road. Bye the way, anyone need an old slant six? :)
 
340mopar said:
Rumblefish from what I have read on the history of the "Express" the Lil Red Express motor is the same as the E-58 360. I was going to mention that motor but could not remember the E-58 part.
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As some may know the E-58 motor came in more that just the trucks. You can look at Cordoba's, Magnums and the 79-300 had the motor as well.
 
The reality is regardless of what you read there is no better year. If you have a block that's not cracked, and you're building for less than 425hp and stock stroke, any year is fine. If you're building a 4" stroke, or something that will exceed the 425hp, you should get any year sonic tested to make sure it's not core shifted. If it's thick enough, it's the best year. Some 1971 blocks were cast with 340 cores. Providing those cores were set by someone that paid any attention, the blocks should be thicker cylinder walls. that guy didn't work much from what I've seen/tested. That's for early '71 castings only. By '72 360s had thier own cores. Again, if there's no core shift, any block will be thick. However Mopars really suck for casting core shift and about 50% require sleeves to correct one or two cylinders worth of problems for high hp packages.
 
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