I don't think I have ever (or at least seldom) written, But I, like Pat, do a lot of this type stuff---and your choice of a 400 block ( with the smaller)(altho bigger than most engines) is the best choice Pontiac to use as The 455 block has even bigger main sizes---and with the stroker cranks with the Chev bearing sizes out there are good candidates for moveing up the cubes to the upper 4xx's-


Not only does the 455 have much bigger mains for the bearing size but that makes the distance fron main bore to cam bor shorter and easier to split------