For me it would be a screw blown/supercharged Gen III Hemi.
Retain all streetability, valve train stability, on pump gas.
Change pulleys, load EFI tune and add race gas ...go 8s in an A body.
The LS clowns have been doing this for ages. Ill take an OEM Gen III block over any OEM SBM or BBM block any day of the week for power handling ability.
