As with Jim above, I am also running BRC Forged pistons in my 63 - 421 bored 30 over (~428).
BRC has a very good tech dept should you have any questions.
(386)364-5623
However, I did not purchase them directly through BRC,. Mine were purchased through
Ken at Ken's Machine Shop
512 S. Main Street
Brooksville, FL 34601
Phone (352) 796-8800
Email:
[email protected]
http://www.angelfire.com/fl4/pontiacdude428/
Ken helped in determining the correct dish-out which enabled me to run on pump gas ~ 9.8 compression ratio.