[tmoss]

The problem you will have is with idle if you can't maintain enough vacuum to keep the EEC from seeing the motor as "under load". The SD EEC uses vacuum to the MAP to judge when the motor is accelerating (under load) and lower than factory vacuum readings make it give too much fuel at ilde.

Rhoads now makes roller lifters that might help the idle out a lot. They are a variable duration lifter. They have a patented machined groove in the lifter plunger that bleeds off oil/duration at lower cam speeds. The bleed off rate is not enough to affect duration as cam speed increases. I ran the flat tappet version of them years ago in my 67 Camaro 383 to take a Comp Cam's 292 idle.