I think for small block P5's hands down.
Big block hemi99 would be on top. Not sure which would be better between stage 5 millenium and preditors both can make good power.
I just bought this car which has millenium stage5 on 604" with 12-1 made 1145hp and 880fp. Has any one seen it before?

Peter. Australian Charger, alloy block injected 410in, w9 na 9.03@148 leafs 3000lb

1967 barracuda 605 hemi Stage5 millennium 8.2@170