512 B1 heads HP?

Nothing. Sounds like someone can’t tune right.
get too much power out of a stock 440 block and u know it will split the block between the cam and main webs , perfectly tuned or not , its the h.p. that does it mostly, unless ur flat out hammering the hell out of the engine w/ a bad tune -----------huh??
No doubt u know how to make h.p.-------------