1964 - 1967 Ford Mustang Tremec Transmission Conversion Installations
Installing a TKO into a 64-67 Mustang already equipped with top loader manual transmissions is a relatively simple task. Your clutch, bellhousing, speedometer, slip yoke and driveshaft will work. You will need to modify the cross member, and you’ll need to “lift” the tunnel about 1” to have enough clearance.
For a 428 Cobra Jet, you'll need a Clutch disc, pressure plate, throw out bearing, fork, cross-member and again, the tunnel needs a little massaging. There is a cross-member out there that drops the back of the tranny for more clearance, but that is not the right way to do it.
The correct way is to lift the tunnel. Your driveshaft will be the same length as stock, and you can use your bell-housing without an adapter plate.