[oyoung]

HELLO I hope I ain"t getting hooked on this stuff.however I"ve heard of 425ci.heads going on to 472ci engines, is it at all possible for pre 1974 472ci heads to be installed on to 425ci.pros&cons please
Thanks

 

[davesdeville]

Well, pros would be much better flow and increased compression ratio, just off the top of my head it'd probably be around 10:1. Run the numbers through a calculator though to figure out exact... 425 heads are 96cc and the old 500/472 heads are 76cc.

Cons might be headgasket issues, you'd have to run 4.3"+ gaskets. I'm freakin tired so there are more than likely things I'm forgetting, someone else should chime in soon.

 

[Night Wolf]

I know one of the head swapping yeilds a 12.5:1 compression, I think that is 425 heads on a 472/500

I am not too sure about 475 heads on a 425 though.

 

[oyoung]

What is 4.3"+ gaskets?

 

[terrible one]

425 heads on a 472 would just do a lot of restricting. They don't raise compression that much. 76 cc heads on an engine that came with 120cc heads will yeild 12.5-13:1

 

[oyoung]

The ? was what happens with pre 1974 472/500 heads installed on 425ci or if at all possible
THANKS

 

[terrible one]

Well, pros would be much better flow and increased compression ratio, just off the top of my head it'd probably be around 10:1. Run the numbers through a calculator though to figure out exact... 425 heads are 96cc and the old 500/472 heads are 76cc.

Cons might be headgasket issues, you'd have to run 4.3"+ gaskets. I'm freakin tired so there are more than likely things I'm forgetting, someone else should chime in soon.

Looks like your question has already been answered.

4.3 is the bore size

 

[oyoung]

Hello does anyone have any idea what a 425 weights