I tryed when building my 428 to keep it streetable. The problem you are facing we all faced. Are you getting any wheel spin? Are you getting any bog when you launch your car? What size tires you running with your gear? I am with everyone here pontiacs like 12-14 degreees initial timing and 36-38 total timing. Old pontiac guy said he always used the ear because you can hear when the car has the timing it wants.