I've got Rocky Rotella's book on building big power Pontiacs and there's a chart in there of all the Pontiac V8 cranks and their dimensions. I wanna say the mains are 0.25" larger. If I were gonna go that much bigger on the 400 block, I'd probably invest in splayed caps as well...but again, I catch myself and have to remember I'm building a street motor that I want to live a long life...not a race motor I'm sparing no expenses on.
