340 J heads on a 318?

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myasylum

myasylum

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I have been doing a lot of reading about heads, and most of it seems to be related to 360 J heads on a 318 is a bad idea because Of lack of compression, and that "302" swirl port heads were the way to go.
I did however find someone selling 340 J Heads (202/160). would that be the same issue as the 360 heads?

Any thoughts? Thanks!
 
Yes it would be. Are you building a engine from the ground up and a screamer at that? If so, these would be the heads.
 
No this is a stock 318 with 67,000mi. That's why I was wondering if these 340 J heads would be good, or if I should keep looking for the 302 heads.
 
I'm not sure what your doing to the engine performance wise. Do you have a thread going on it?
 
302 heads are closed chambers with small valves 1.78/1.51 compression builders. Velocity will be high
J heads are open chambers with big valves will not build compression like the 302s. Velocity will be lower than the 302s

On the 318 I would use the 302s and a Perfromer intake. Mill the heads to bring the compression up. Also you can use the thin Mopar Performance gaskets to help kick in a little bit more compression.
 
I was looking at these a few weeks ago. I think there was something about charging an additional $100 in the event of no core. Seems decent if nothing else pops up. Probably some craptastic valve springs, but that's an easy fix if need be.

302 heads on ebay
 
My setup.

318
#302 heads
Edelbrock LD4B intake
Mopar cam .430 intake .450 exhaust P4452759
Mopar valve springs that go with the cam, {340 springs work too}
Dual exhaust off the stock exhaust manifolds.
Summit copper exhaust gasket between head and manifold.
Stock tranny, stock rear {SUre Grip 2.94}

http://www.youtube.com/watch?v=Ud8mci4rjFU

Part Number: DCC-4452759
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,200-5,200
Intake Duration at 050 inch Lift: 221
Exhaust Duration at 050 inch Lift: 228
Duration at 050 inch Lift: 221 int./228 exh.
Advertised Intake Duration: 260
Advertised Exhaust Duration: 268
Advertised Duration: 260 int./268 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.430 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.450 in.
Valve Lift with Factory Rocker Arm Ratio: 0.430 int./0.450 exh. lift
 
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