You'll note they put in the 4.06 final gear.
All V6 MTX-75's have that final drive already.
Matter of fact some have thought about going to the Zetec's taller final drive (3.82 as they listed) to help with traction both from a stop and out of turns.
Turning the tires over (lack of traction) is already a problem so more gear would be a bad thing...
