To do a Comparison is easy.
With a M20 you launch real good and then fall on your ass when you hit 4th gear.
The RPM drop is aroung 1,000 RPM in each gear till you hit 4th where you drop 1,500 RPM, which will really kill your ET's. The M21 is more even at 1,000 RPM drop in each gear all the way through. less RPM drop the longer your motor is up in the power curve.
Pantera
