Improved Cooling 345

sonic1313 said:
so, I am new to this forum. I have a 392 block with new pistons and rings. Trying to understand what has been said--I have a 392 e with a build of r (70). With this block, the guy gave me 345 heads off an x (74). The 392 is not an ic...so, is the block and heads compatible? If they are, they don't look like they match up. What do you guys think? Or is it stupid to use 345 heads? Thanks!!!!
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Sorry...I can't help with this question as I have not tried it or validated and don't deal in "maybe" or "I think"!

Just comparing a 345 head gasket with a 392 head gasket, I can see a possible interference issue between the 392 piston top and the 345 head in the "squish band" area. Inna performance engine build that could be compensated with some serious machine work after calculations were verified.

Someone else around here May have tried this and has direct experience and not just hearsay about this idea which is very common unfortunately!
 
Thanks, I didn't think it looked right either...but I have been hearing chatter 'bout this combo. Guess I;ll keep searchin or just buy some 392 heads. Dang! Was all excited about uppin the compression.
 
sonic1313 said:
thanks, I didn't think it looked right either...but I have been hearing chatter 'bout this combo. Guess I;ll keep searchin or just buy some 392 heads. Dang! Was all excited about uppin the compression.
Click to expand...

The combination you hear the chatter about is a non-ic 392 and 345 heads. As you've discovered the 345 heads you have will not work with your block. If I were you I would invest a bit of time looking for 392 heads, but be wary they are the correct ones. I have heard the ic heads are getting hard to come by.
 
I think I am with you on the 392 heads. But my engine is less than 1013196. It's in the 900's. So, that means it is a non-ic. Correct?
 
I found this on offroad.com. 392 builds-"the heads are also interchangeable, with the port size being nearly the same. However, the 392 has larger, sodium-filled valves. Exhausts are 1.734 versus 1.609, with intakes of 2.078 versus 1.979. These sizes are adequate for the engine's limited-rpm capability. The exhaust ports themselves are quite restricted, so if you're planning an "all-out engine," some quality porting work will be necessary. Pay particular attention to the cylinder head years; starting with no. 1013196 there was a change in the cooling design. A different head gasket is necessary -- the water leaks told me so."
 
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