Well in the Gonkulator it depends a little on which intake, and of course depends a LOT on headers vs iron.
So here are 4 depending on what you run on the dyno. Assuming a 1" 4-hole spacer on all the intakes.
35t418 51p372 (Torq 418 at 3500, Powr 372 at 5100) your usual dyno headers and 390HP intake
34t408 50p358 with 352HP intake
36t408 51p343 with 2" flat iron logs and 390HP intake
35t400 50p333 with 352HP intake
Good luck Brent and thanks for helping keep the FE hobby alive!
NOTES FOR FUN:
* A 600 Holley cost about 3hp on top, nothing down lower. A side hung 600 would look very period correct.
I also gonkulated the dyno headers & 390HP intake version with:
36t424 52p383 stone stock C8OE-N CJ heads
36t423 54p392 stone "stock" CCJ heads (not really from Canada, "dreamer" heads I guess)
I am still learning about those amazing CCJ heads. They may well explain why "Cobra Jet Corner" is so big back in the NHRA Superstock era.
The 428CJ was totally dominant in the SS/8.50 to SS/10.00 classes. Just a sporadic winner in Stock class. I think the CCJ heads were one of many factors.
Hard to find data on these heads, still hunting.
