Jim, I have never used a SV for a BBM, so I really can’t answer that.
However, a 572 I built that used 572-13 365 heads and the 3x intake made peak tq at 5600. That manifold was just port matched to the heads. Those heads have ports with a larger cross section and bigger valves than some EZ325’s, so I have to believe at least some of the higher peak tq rpm is attributed to that.
That isn't much difference for the big increase in volume. Were the cam specs similar? I'd be disappointed if I told the owner of this engine he could pick up power by switching to 572 heads down the road and then found out that it didn't move the peak much.
The customer wasn’t looking for a high rpm screamer. He wanted something low maintenance. I freshened that motor after a few seasons(250 passes), and it was like new inside.
It made peak power at 6800(918hp), and he shifted at about 7k. Ran a best of 8.33@165 in a 2750lb car. The 918hp was with an 1150 carb. In the car he ran a 1050 I reworked that was down about 10hp on the dyno.
The cam was 283/292-12.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
