[John DiBartolomeo]

I switched from M1 to M3 when it first came out and after fattening the carb up roughly 10 jet numbers, we picked up almost a tenth. When VP came out with the M5, they said it was even better. Tried it - jetting up and down, timing in and out - and never saw any improvement over the M3. The people I spoke with who picked up with the M5 went from M1 to M5, so I can see the difference. The problem I had with the M5 was when you backed up after a dragster burnout, the fumes would kill you. I've gone back to the M3 but agree that it's hard to get. I use it in both of my dragsters and make sure I have a drum with me before we leave the shop. Generally, I believe the timing might not see much but it definitely requires jetting up. However, the timing issue theoretically should require changing because of the burn rate of the fuel, I just never saw anything. Call me if you'd like. -John D.