Put a 315 pro on it. I'd definitely spin it higher w/ those big heads and manifold.
I'm also very surprised it needs that much jet. My 1200 dominator (mod'd 1150) is 88/96 w/ a PV up front.

CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax