340 heads on a 318

[phf]

would putting 340 heads on a 318 improve power outputs over putting a set of 360 heads cut .060in?



thnx  stan

[Jacksboys]

humm...which 340 heads?, are they ported?, what is the compression of the 318?, cam?, etc.?

[GoodysGotaCuda]

humm...which 340 heads?, are they ported?, what is the compression of the 318?, cam?, etc.?

I agree. For the most part...340 heads arent much different than 360. (i wanna say they are the same, but i rather not sound that stupid if not lol. Xs = 340 Js= 360...but really arent different? )

[heminut]

The only real difference between the 340 heads and the 360 heads is that the 340 heads have a slightly larger intake valve.

[GoodysGotaCuda]

The only real difference between the 340 heads and the 360 heads is that the 340 heads have a slightly larger intake valve.

Were the 340 heads all 2.02? and the 360s were 2.02 or 1.88?

[Super Blue 72]

   I'm curious about this too.   

I know that some 340s had the smaller 1.88 valve, maybe starting '72 with the low compression engine, but these may be 360 heads, I dunno... 

[tactransman]

'71 and earlier had the 2.02 . I put 1.88 360 heads on a 318 in a '77 PU truck and it screamed, especially on the highway. I would think 2.02 would be too much for a 318, probably shroud the intake valves by the  block bore size. 

[Chryco Psycho]

I would be looking at the swirl 308 360 heads with the smaller valve for a 318 

[GoodysGotaCuda]

'71 and earlier had the 2.02 . I put 1.88 360 heads on a 318 in a '77 PU truck and it screamed, especially on the highway. I would think 2.02 would be too much for a 318, probably shroud the intake valves by the  block bore size. 

my boat anchor mill has 2.02s on it, milled. probably shrouded decently i'd assume.  runs fine though. 

[heminut]

'71 and earlier had the 2.02 . I put 1.88 360 heads on a 318 in a '77 PU truck and it screamed, especially on the highway. I would think 2.02 would be too much for a 318, probably shroud the intake valves by the  block bore size. 

As far as I know, all the 360's had 1.88 intakes. After 71 I believe they used the same heads on both 360 and 340 engines.

[phf]

so is there any difference in flow-ability between a 1.88 360 head,casting 308 and the 1.88 340 head, casting 915?

[Chryco Psycho]

yes the 308 is better

[phf]

ok, thank you