Sucks to hear about the new MSD HEI module. I really like the Ignitor 3 module, a rev limiter and almost multi spark. I have blown 2 of them, one was my fault. The other, I had an issue with the power wire, not putting out enough voltage and it died. I have it in my 88 Cutlass, right now. I would check how far the secondary air door is opening, betting it is serverly limited. Cliff's book shows how to measure and it has different recipes for different motors. Also probably your extremely lean secondary rods are limiting it. I can feel my secondaries open and feel the rush on my 70S.