I've been running a mach3 for a while. But, I think I'm way off on the timing and gearing.
45* timing and 34/69 gearing with a fan. It has no bottom end punch, but a fast top end.
I ran the same setup with a mach2 and it was great.
I'm going back to 20* and 32/69 or 31/72 and starting over with the setup.