I read in the article that was written that there was no need to find "848" head (which requires steam hole drilling), for the modification of the 261 engine. I believe the 848 head has a compression ratio of 8 to and the other heads were slightly lower. Since I have an extra 848 head in my garage would it be better to use the 848 head and drill out the steam holes or the standard 261 head?

Would that change the C/R from 8 to to another C/R when using the 848 head?

Secondly, I read again in a different book that on the 235 you can mill the deck .020 and shave off the head if I remember correctly .040 and you could still run pump gas and get a little more performance. Forgive me I not sure of the head shaving number. Now would you also want to do this with the "Cadillac 261" or will that open another can of worms?

What's the advantage of using moly pistons vs. The standard ones ?

The 1954-55 261 block do they have shims under the main caps like the 1955 235 block?

Last edited by Tiny_Jaime; 10/02/2014 5:34 AM.
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my sweet ride." -Amen

56 Chevy 3100