My experiences with N/A SB with stock type heads and with BB with the same conditions is that they both liked closer LSA, IE 106 to 100. My expereinces(dyno testing and at the track) is the closer the lobe centers and having the intake lobe centers advanced built more power under 6000 RPM. Once the the motor are modifed for higher RPM use then the wider LSA help move the power range higher up in the RPM range, above 5000 RPM. Of course when doing that you need a looser converter, diffferent gear ratios, trans and rear end, better cam, more lift and duration, and associated valve gear, bigger intake sustem and fuel supply and so on Ultimately speed costs money, how much do you want to spend and how fast do you want to go, HUH Al