"Power always finds the weakest link," is an adage to always be mindful of whenever you're making changes that will bring a Mustang's horsepower, and especially torque, to new levels. So, with the level of performance we expect to see from the Cleveland-headed monster in Greg Montoya's Pony being unknown, we decided to make additional drivetrain changes to support the newfound power.
Before removing the supercharged 306 and stock T-5 transmission from Greg's '89 GT, we noticed the tranny was not as smooth as it should be (grinding on the Second-to-Third shift), and it definitely was starting to produce more noise than it ever had. In anticipation of making power well above that of the previous drivetrain, your tech editor and Greg decided the time was perfect for exchanging the 'Stang's worn-out clutch and transmission.
Tremec's TKO 500 got the nod, along with a Force 10.5 dual-disc clutch from Ram Clutches. In addition to the clutch, if you go with a 26-spline (input shaft) unit like Greg did, the transmission transition requires a new bellhousing, shifter, driveshaft slip yoke/modified shaft (the TKO 500's output shaft is 31-spline versus the 28-spline output of a T-5), and a modified crossmember.
AMP Performance in Phoenix, Arizona, is a great source for all of the parts you'll need for the upgrade. While installing a TKO 500 (or TKO 600 if you're making really big steam) isn't mandatory, we think making the change is a good proactive step toward being able to fully enjoy a new engine without worries about power getting to the rear wheels.