Hey guys,

I have a couple spare chevy inline heads in my shop. I'm wondering if they are worth holding onto for a future performance build-up or if you guys have any info on these. Are they all the same valve and chamber size?

Casting numbers:

331184

3847990


I have a 292 with a 3927763 head currently on it. I am planning to build it up as a street motor with 3x1 intake, headers or a split manifold, with a mild cam. Would there be any advantage to swapping either of the above heads onto the 292? Does anyone have any info on the -763 head? Same chamber size & valve size? The 763 has the smog ports in the head, where the above heads do not. Do these smog ports have any effect on airflow, or is it a non-issue?

Thanks!

The air injection ports really does not hurt airflow.

It does make it easier to install EGT probes.

MBHD

Is there really no substantial difference between these three cylinder heads?

Santucci's book shows the -184 and -990 to be 250 cylinder heads, and the -763 is a 292 head. Are they all more or less the same as far as port/runner size, valve size and chamber size/design?

Thanks to anyone who can clear this up for me

To my knowledge, there is not much difference at all.

The only one that is different is a cyl head off of a 194 CI 6 cyl engine = smaller chamber.

MBHD

OK, thank you very much for confirming this!

the 331184 250 head had either a 72.76 OR up to a 74cc chamber, Most 250 heads had that much range in chamber size.
A 230 had a range from 72.38 Up to a 75.5 chamber, and some 194 heads had a range from 60.32 to a 72.80 (yrs. 62-67)

Yikes!
What would the compression be w/a 72.8 cc head on a 194 CI engine?
Piston down the hole, etc. 7:01

MBHD