hi George... I think the big difference between our numbers came from the cam duration. Hopper said he's using a 242/242@.050 and you used 296/302 (seat-to-seat?). For heads, I used flow numbers for 441 and added 10cfm fudge to account for the larger valves. I think the Torker intake is limiting top end, too.

I ran again with new bore/stroke.... (BTW that comes to 379.7ci with 4.155x3.5")

With Torker ("dual-plane high torque") intake:

381hp@5000 / 479ftlb@2000-2500 (no change with bore/stroke)

With "RPM air gap-like" ("dual-plane max flow"):

446hp@5500 / 474ftlb@4500

That's a huge difference from the intake manifold.

-Chris