FWIW--My Super Gas car with 447 C.I. Low-Deck (.020 over 400 block)

Unported Victor heads, compression around 14 to 1
850 DP Holley carb
Victor 383 intake manifold
Step headers 2" to 2-1/8"
Comp Roller Cam 23-999-3

At sea level tracks would run 154 MPH. Car with me and ballast aboard weighs 2250. I think that computes to 643 HP.