Well it's not quite in the 'Cadillac Tax' territory of what it costs to pay Cadco for hop up parts for a 500 Cadi V8.. but hey, whenever you're getting into modern day engineering time and manufacturing effort for a 50 or 60 or 70 (OK, pushing a century now for the Stovebolts) year old engine, then you'll have to pay for the small batch runs and large engineering hours required to make them.

The cheap way is small block Chevy, the modern way is LS.. but some of us think outside that box :-)

1965 C60 school bus | 1967 GMC 6500 school bus