360 year differences

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Cudakyle

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Bonney Lake, WA
I have a '65 Barracuda with a 273 and 3-spd manual. I am wanting to go 360/727 and bracket race with the car. The goal is to run 13.00. I found a guy local to me with two complete 360 engines. One is a 1971, the other is a 1974. He wants $75 for the '74, and $100 for the '71. My question: what is the difference between these two engines? Which one should I choose for my barracuda? Thanks!
 
Some people will say that a '71 360 has the thickest cylinder walls of all of the 360's but is hard to say. If the motors are complete with heads I would go with the '71 because if they are the stock heads they will be a #3418915 "J" head. These are probably one of the best stock iron heads.


Chuck
 
71 has better compression and on paper more power. here are the specs for the 71 and the 74:

71:

255 Horsepower. . .. ..
V8-360 2 Barrel 4.00 x 3.58 360 8.7:1 255 @ 4400 360 @ 2400 45-65



74:

180 Horsepower..…
V8-360 2 Barrel 4.00 x 3.58 360 8.4:1 180 @ 4000 290 @ 2400 45-65

200 Horsepower..…
V8-360 4 Barrel 4.00 x 3.58 360 8.4:1 200 @ 4000 290 @ 3200 45-65

245 Horsepower..…
V8-360 4 Barrel 4.00 x 3.58 360 8.4:1 245 @ 4800 320 @ 3600 45-65
 
I wouldn't worry about the heads, all 340/360 head castings until magnum heads have the same port size shape and will flow the same amount of air. Only difference would be some of the J heads had 2.020" diameter intake valves which certainly aren't needed if your goal is 13.00 in an early A-body.

Also the advertised horsepower difference between 71 and 74 is a function of the change in the way power was measured not any changes that were made.

I would assess each engine and take the one that is the most complete or appears to be in the best shape. In either case they will likely need to be rebuilt .
 
Like the compression and HP ratings, the head flow of the later 360's my be similar to the "J" but is not the same. But regardless on the flow, the "J" heads are more sought after so they are worth more to people. Just look at what they sell for.

But of course swingtown has the right idea on buying both, I was just trying to tell you the differences between to the two since that is what you asked.

Chuck
 
FWIW, the only difference in flow would be casting variations from head to head, meaning you could have a latter set that out flowed the J's or visa versa.

A J head may fetch more money but that's because there is an unfounded belief they are better. A smart shopper would go for the latter heads becuase they are a better value.
 
Thanks for the information everybody. Maybe I will make an offer on both so I can pick the better block/crank/rods between the two. I can always sell the other one later. I'll be going to look at both tomorrow afternoon.
 
Again, I was pointing out the differences like asked and I didn't say it was the best head I said one of the best heads meaning there are others just as good.


But according to the Mopar engine manual, the intake ports do flow same but the exhaust ports do not because of the hump in them for the AIR port. Granted this can be ground out and made to flow the same as the "J" head and would be a better value but they are not the same as cast. Unless the Mopar manual is wrong.


Chuck
 
340mopar said:
Again, I was pointing out the differences like asked and I didn't say it was the best head I said one of the best heads meaning there are others just as good.


But according to the Mopar engine manual, the intake ports do flow same but the exhaust ports do not because of the hump in them for the AIR port. Granted this can be ground out and made to flow the same as the "J" head and would be a better value but they are not the same as cast. Unless the Mopar manual is wrong.


Chuck
Click to expand...

My '74 Ramcharger had "J" heads and no facility for the air injection port, nor did it ever have an air pump. Might be different for a car engine. Just my 2 cents worth. :)
 
The later 360 head does have the ports that's why the exhaust doesn't flow as well as the "J" head unmodified. I am obviously having trouble explaining it so I think I will just retrack what I said on everything.

Cudakyle disregard my posts.

Thanks,
Chuck
 
heres what to do, buy both engines. sell all four heads on ebay then buy a nice set of edelbrocks alum jobbies. they flow good and are way light. problem solved!!
 
swingtown said:
heres what to do, buy both engines. sell all four heads on ebay then buy a nice set of edelbrocks alum jobbies. they flow good and are way light. problem solved!!
Click to expand...


ditto :)
 
I dont think you'll get enough money to by edelbrocks from selling 2 sets of J heads. If so I just sold Rumblefish a set of Magnum heads way to cheap.
 
340mopar said:
The later 360 head does have the ports that's why the exhaust doesn't flow as well as the "J" head unmodified. I am obviously having trouble explaining it so I think I will just retrack what I said on everything.

Cudakyle disregard my posts.

Thanks,
Chuck
Click to expand...

Chuck,

I see what your getting at and I should have been more clear. What I meant was that I have '74 "J Style" heads that are original to the truck but they do not have the air injection ports. I have the casting number written down somewhere just not here. Am I wrong in my assumption that the air injection heads did not show up in production until '75? :-|
 
Well, I got them both. The guy wanted them gone, and I got them both for $75. :) Here's the casting# run-down:

Engine 1: block: 3418496-4-361
heads: 3671587

Engine 2: block: 4006830-360-5
heads: 3769974

Engine 2 has the heads off, and the cylinders look really good. Engine 1 is complete- I pulled a valve cover and cleaned lots of sludge to get the casting#. Both have rear-sump oil pans. What do I have here? Any good? What are the differences between these two engines?

I have a set of heads that I bought a few years ago, casting# 4323345. They have the 360 designation on them. They have been ported quite a bit, have 2.02 valves with the chambers worked to unshroud the intake and exhaust. These were the heads I was thinking of running. I'll probably follow one of the build-ups on the 360 build thread on here. What do you think? Thanks for all the help!
 
Sorry I'm late on this but the 71 engine is a truck only because the passenger car engine didn't come out till 72. I may be wrong but better main webbing and a better crank at least this is what mine had.
 
This should be of help!

Casting Number Engine CID Year Intake Exhaust
2465315 273 1964-65 1.78 1.50
2536178 273 1966 1.78 1.50
2658920 273 1967 1.78 1.50
2843675 273 1968-69 1.78 1.50
2658920 318 1967 1.78 1.50
2658234 318 1967 1.78 1.50
2843675 318 1968-74 1.78 1.50
3769973 318 1975-83 1.78 1.50
4027163 318 1977-86 1.78 1.50
4027593 318 1977-84 1.78 1.50
4323302 318 Fast Burn 1985-86 1.78 1.50
4323345 318 Police 1983-86 1.78 1.50
2531894 340 1968-70 2.02 1.60
3418915 340TA 1970 2.02 1.60
3418915 340 1971-72 1.88 1.60
3671587 340 1973 1.88 1.60
3418915 360 1970-72 1.88 1.60
3671587 360 1973-74 1.88 1.60
3769974 360 1975-76 1.88 1.60
3671587 360 1976 1.88 1.60
4027569 360 1977-86 1.88 1.60

It appears one engine has '73 340 heads and the other has '75-'76 360 heads.
 
Here's the block casting numbers:


CASTING # C.I.D. YEAR GROUP
2465330 273 1964-66 LA
2536130 273 1965 LA
2466090 318 LA
2536030-318 318 1967-75 LA
2566080 318 LA
2806030 318 1967-74 LA
2780930-340 340 1968-73 LA
3577130TA-340 340 1970-71 LA (Trans Am)
3418496-360 360 1971-74 LA
3870230 360 1975-UP LA
2264230 318 1960-66 A
2468230 318 A
2532630-318 318 A
 
I saw a truck in PYP that had a 360 with a car pan on it. A buddy of mine had pulled the J heads off of it and mentioned the casting date was 70. Sure enough I went and looked at it and it had a casting date with 70 at the end. Don't remember the month. What about that?

I had a 75 360 out of a van that didn't have the injector ports drilled but the bumps in the exaugst ports were there.
 
Hey, I just put in a search for the casting numbers of 360 blocks, and I have the same casting # as you, and a casting date of 9-28-77. It has dish pistons, but the dish looks shallower than other 360 pistons I've seen, and I have some heads that are 596's . They have the air injection hole. Does anyone know about this block casting, was it a good one? and as for my heads, what were the cc of the chambers?
 
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