I'd talk w/ Dwayne Porter before you jump ship and build a wedge. He spec'd my cam and springs. No issues here and we're using "similar" setups.
I have DLI roller rockers, MP shafts, and MP stands on MP heads.
You obviously have something wrong...whether it's the cam/spring combo or an oiling issue, I don't know.
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
| 
