Well...it's going in a mag, so I'll be vague. We tried TTI 1 7/8 x 3" and 3.5" collectors, spacers, moved the cam around, lash, 3 carbs, timing.
Father time was kickin' our but on this build and just ran out of time to try a different cam combo.
Cam was in the 260's @ .050 and lift was mid 600's.
OOTB 1000HP did very well against everything the PC 1000HP and PC dominator but the dommy was KING from 4000rpm to redline!