[ZeGermanHam]

Originally Posted by i82much

that’s a lot of effort for a street engine just to go to a 3” main block, no? is the juice worth the squeeze?

Maybe, but it depends. You can usually find good standard bore 400ci blocks for around $500, and Butler rotating assemblies start at $1800. OP says he wants to build a "high horsepower" motor (a subjective term). By the time you sell the 455ci block, it's within a thousand dollars difference (give or take). And with that in mind, I'd rather have the the 400ci block with the smaller/stronger mains and future-proof it to handle whatever power gets thrown at it down the road. And I assume he'd have to bore the 455ci block anyway, and then new pistons would need to be purchased, further narrowing the price gap.