If you're really "only 12.5:1 with that cam you're going to need at least 50:50 race gas but if the car is really light and has a deep gear and a loose converter you can probably run it on the street if you put in an MSD dash mount spark retard. I wouldn't go WOT with pump 93 tho. What intake are you running? If your manifold cant outflow your heads it will kill power and may it more prone to spark-knock. A 3 1/2" is will raise the torque and HP curves, a 3" will lower the peak torque rpm and also the rate of rise of the HP trajectory