I did a 572 back in 1995, made 975 hp @ 6500 on pump gas , 14 lbs, EFI and emissions legal in California. I did the dyno work in Huntington Beach on Pfaff's Dyno.
4.5 bore
8.0:1 dish
4.5 stroke
STOCK 076 GM aluminum head 2.19/1.90 , they were port matched, but no port work done.
Crane .708 lift, 274-280 @ .050 110lc
BDS manifold
10-71 Mooneyham
Bird with 16 nozzle EFI , Lee Performance ECU
It made equal torque also.