When we initially began Project Shark Attack, the car desperately needed an overdrive transmission of some sort. At the time, PSA was using the old school Borg-Warner T-10 four-speed, so a new tranny was a high priority. We initially wanted the O/D to slow the engine down and reduce some of the noises associated with the higher rpm of the original Borg-Warner. Engine and transmission heat is also lessened when the rotating pieces are slowed down, so when we chose the Keisler Engineering Tremec O/D five-speed, the choice was a win-win situation. At that time, the fuel costs were relatively cheap. It's hard to believe when we began the project, premium fuel could be found for $1.50-$1.75 a gallon, and we thought that was outrageous. With prices hovering around $3 a gallon, we're now ecstatic about the change to a more favorable tranny. higher gas prices are here to stay, and the Keisler Tremec PerfectFit five-speed O/D transmission makes the road trips easier on the wallet.
We contacted Keisler and gave them our engine and differential ratio specs and an idea of what we would be doing with PSA. They then assembled a complete package for us that had all the necessary pieces for the install including hardware. They suggested their TKO-500 kit that also included a new driveshaft ready to install. The only trip we had to make was to the local GM dealer to buy three quarts of GM Synchromesh transmission fluid. The supplied speedo cable for the Keisler Tremec is a hybrid GM-Ford unit, and it's nice to know that it's one less thing to locate, plus the correct speedo driven gear is calculated and supplied for you.
The Tremec five-speed O/D has an integral back-up lamp switch in the transmission case so there is no linkage to be concerned with and no external switch next to the hot exhaust pipe like the original four-speed. For added safety, the five-speed transmission has an integral neutral safety switch that can be easily connected to the starter system. Another amenity is the integral Vehicle Speed Sensor (VSS), which can be used for an upgrade to fuel injection that requires a VSS or if you're installing an aftermarket cruise control.
If these points don't make a case for an upgrade to O/D, this little tidbit of info might do the trick. The Keisler PerfectFit five-speed requires no cutting of the floor or tunnel of your Corvette. The shifter is offset, allowing the shifter to be installed in the stock location with the stock shifter boot. Tunnel clearance is an issue at the top of the Tremec transmission, so the Keisler unit allows the install with adequate clearance.
The only issue for the installation is the bellhousing and transmission has to be installed as an assembly if the engine is in place. Actually, it's a loose fitting assembly. The bellhousing is placed on the transmission, then the transmission is put into position with the bellhousing bolted loosely so you have room to install the clutch pressure plate. Once we did the first install like this, we found the task was much easier than we anticipated.