318 cylinder head choices

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snowmobiler7c

snowmobiler7c

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I have been looking online for a few hours at choices for cylinder heads. I have a 70 dart swinger with the origional stock 318 which i have out of the car due to preparing for paint soon. I want to get some ideas for my engine. It is going to be a street/summer toy. I already have a 8 3/4 with 3:55 gears. I would be happy with around 350hp which i beleive shouldn't be too hard to acheive. I was going to go with x heads or j heads with the 2.02 intakes but have decided against it after reading other posts. I have pretty much narrowed it down to just rebuilding my stock 318 heads and going with 1.88intakes, buying the #302 casting heads and going with 1.88intakes or trying to find a set of j heads with the 1.88 valves.

From what i understand i could pretty much just bolt on the #302 casting heads but i would need to know what pistons to go and have the j heads milled to get a decent C/R correct?

Am i looking at a big differance performace wise on either of the 3 sets?

thanks for any input or ideas on other heads.
 
Yes and no.

The 360 will loose a little torque down low and take a decent RPM to recover/over take a stock 318 head, while the more expensive route of modifying a 318 head will deliver all the torque down low and good HP up top.

In other ways to look at it;

On the cheap, a milled 360 head is excellent
A more expensive valve upgraded 318 head is also excellent
A 302 ported with 360 valves is best but costly but IMO best.

What cam are you planing to run?
 
honestly i have not looked into any cam or pistons yet. Im doing the underbody/rear axle/front suspension and disc brake swap hopefully all this month then send the car for paint. Im trying to get a little head start on the engine so im not looking for heads and paying a premimum. any suggestions would be greatly appreciated my only other rebuild was a 318 with mostly stock parts and my built 302 in my 88stang. I beleive i have heard alot of good thing about the xe268 cam? Other than that i know for sure i will be trading my mopar performace single plane for a rpm airgap or buying one.
 
I think in terms of ease of aquisition and potential a set of Enginequest Magnums might be the best choice. They have the best chamber, a well designed port, and will move plenty of air for a 318. I would pair it with the XE262 as the 268 might be too much with the 1.6 rockers. You can get a set of them ready to go for under $800. To properly go through a set of older ones will cost more in most areas, and the bigger 340/360 heads IMO will just lose you compression and not help too much in terms of detonation resistance.
 
stock 318 open chamber heads are around 68cc's, the bone stock 675's I have a t least.

the heads choice between 360-318 port window will either have you building it radical street/strip or mild street/strip.

If you have '170 psi' cylinder pressure, 2500 stall and 3.55 plus gears, I would do the as cast 360 heads with 5 angle vj and small 11/32 stem 1.94/1.60 valves and only port/polish the exhaust [in this case].

And use a cam with 58*-60* over lap for around 9.7 comp

jmo
 
Let me know if your interested in a good set of 302's or 308's.
I'd go $200+ shipping on the 302's, and $250+ shipping on the 308's.

Both sets are stock,...302's have 1.72/1.50 valves, the 308s have 1.88/1.60 valves, removed from good running engines....no cracks in between the seats, broken exhaust stud/bolt or two, but nothing major.

Not negotiable.
 
The 67-70 318 stock pistons are the tallest of the lot giving you the highest CR with any head you decide to use. I'm running these with 302 heads in the Demon.

Haven't leaned on it hard to find out what it will do. 7¼" axle has to survive until the 8.75 gets done. ;)
 
thanks for an offer on the heads guys but i am getting a set of 302 heads for free so that looks like the route i will be going. It seems like that will probley be the best overall choice and i cant beat the price. thanks for the replys
 
On this topic, if I were to run a domed piston with 360 heads on my 318 I have I discovered with my compression ratio calculator that I would get around 9.6:1. Would it be worth getting domed pistons? Or are they a headache with clearance problems? Keith Black makes them. Would I still be missing torque at low rpm? Maybe just get 1.81 compression height pistons with 318 heads instead?
 
Jeremiah -
Are these the heads you had listed on the Seattle craigslist awhile ago? Ive been trying to get ahold of you to find your rebuild specs... milling, final CC of chambers, port work etc. What did you have done to the heads and are they still available?
 
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