View Full Version : What size gears should I upgrade to?

10-28-2002, 07:09 PM
On average, most will suggest that the SCís and XR7ís with the M5R2
transmission should upgrade to 3.27 and those with the AOD(E)/4R70W should
upgrade to 3.73. I would like to suggest however, that the 3.27 final drive ratio
be used for all 89-93 SCís and XR7ís with the M5R2, while the 94-95 SCís
with the M5R2 upgrade to either a 3.27 or a 3.55 final drive ratio.

Since the 94-95 style M5R2 has less aggressive 1st, 2nd, and 3rd gear ratios than
the previous model M5R2, this means that it wonít respond as well to the same
final drive gear when it is backed behind either transmission. The differences
are negligible, but they are noteworthy. Most find the 3.27 gearing to be
suitable for any year 5 speed SC or XR7, but you should be informed of the

With the automatic SCís and XR7ís, a 3.73:1 final drive is suggested because
you will still have a decent top end when 3rd gear is near the redline. When
racing at the drag strip or just opening the car up on the highway it is never a
good idea to do wide open throttle (WOT) shifts into overdrive. With a 4.10:1
ratio or higher, your car might pull harder, but you will find yourself running out
of gear quickly unless you shift into overdrive.