Technical Head gasket effect on compression

Chuck, you gotta work on those typos!

 

...I think that 'Chuck' is worrying too much about nothing. My opinion only of course.
You should consider that the slight bore increase will also add a wee-little-bit to the swept volume and likely cancel the drop from the fat gasket. Nope, not interested in doing the math.
And no, that minor gasket change will not affect the manifold fit.

 

I know that you know that we have a teachable moment here.

 

Just my 2.5 cents. If you have a 68-71 383 magnum. you motor should have 906 casting heads. There is little to no quench with these heads as they are open chamber. You can still get steel shim head gaskets from Mopar Performance. Just remember these gaskets have about a 4.400" bore opening. So you will loose a little more compression over the stock 383 gaskets. The small bore gaskets are very hard to find. Gene.

 

None that you will notice driving it