Not having messed around with Pontiac's much. I thought I could use all stock parts if I found the right years and combinations.
For pistons I'm going to use stock 455 hypereutectic flat tops #L2359NF as you can see in the pictures I posted. It looks like the crank is the only custom piece because of the main bearing size. It was just under 800 bucks. Haven't got far enough along yet, but it's been suggested the push rod length might be an issue too.

1947 M15 Studebaker 454 4x4
1949 Chevy COE
In the Stovebolt Gallery
More pix of the COE
1950 Harley FL
1958 GMC LCF 455 3x2bbl
1961 Chevy C60 Tilt Cab 327
1966 Chevy C60 Tilt Cab 496
1961 Chevy K10 sb 292
1974 Harley FXE
1979 Chevy K10 sb
2007 Harley Streetglide


I'm not that good but I'm slow