Building a car with aftermarket or late-model parts always requires a bit of homegrown engineering. A lot of measuring, head scratching, grinding, cutting, welding, and usually a ton of headaches. One of the most challenging projects has been to put a late model transmission into your car, have it fit, and have the shifter be in a comfortable spot. Usually placing a five- or six-speed trans in a your classic Chevy meant that either the shifter would come up through your seat or you would have to resort to some very unique shifters to get it in a comfortable spot.
Thanks to Keisler Automotive, Tri-Five enthusiasts can chose either a five- or six-speed with all of the engineering done for you. Based on the bulletproof Tremec TKO 5 speed or the equally tough T-56 six-speed, Keisler machines the transmissions so the shifter location comes through the floor in the correct spot, right where it needs to be without having to make major modifications to the transmission tunnel. In fact, most of the kits utilize the stock GM bellhousing (or SFI equivalent). Also available with the kit is the correct length drive shaft, speedometer cable, pilot bearing and any wiring that the transmission may need. With optional accessories including the hydraulic throw out bearing, clutch, flywheel and shifter handle, Keisler Automotive is a one-stop shop for everything between your motor and rear end.
With both the TKO 5 speed and the T-56 six-speed, Keisler offers kits for two horsepower ratings: 475 hp and 650 hp. For the GT55 project, we chose the 650 hp T56 kit to take the abuse of our 530 ft-lb of torque. With first gear at 2.66:1 we will be able to have some stoplight-to-stoplight fun while sixth comes in at a freeway friendly 0.50:1. Our engineer, Katz, has calculated that with a 3.70:1 gear set in the GT55 and in sixth gear we will be able to cruise at 70 mph with only 1,700 rpm registering on the tach. Hard launches and low-rpm cruising, what could be better?
Keisler Automotive has many kits available including packages for the ever popular Nova/Chevy II, Camaro, Chevelle, Corvette, and of course the Tri-Fives. With more and more packages available every day, Keisler Automotive has taken a lot of guesswork out building a car.
In the last few years, the automotive aftermarket has seen a renaissance in the world of crate motor performance. There are dozens of companies producing numerous combinations for virtually every budget. One thing's for sure, the availability of streetable big horsepower crate motors have never been so great at such reasonable prices. To obtain the goals set for the GT55 project, we chose a Bill Mitchell Motown Small Block. While Mitchell has packages that range from 415 to 454 inches, we just had to go with the traditional combo of a 427 inches in a '55 Chevy
Having been in the engine building business since the '70s, Bill Mitchell has enough experience to know what works and what is going to be reliable enough for long-term street duty. When you read the build sheet on one of Mitchell's Motown motors, its like reading a who's who list of the aftermarket that includes: Wiesco forged pistons, Manley 4340 rods, Crane camshaft, Speedpro lifters, Motown aluminum manifold, Modified Holley 870 Holley carb, Speedpro ring set, Milodon pan, Clevite bearings, HEI distributor, Fel-Pro gaskets, and ARP hardware. To top it off all of the Motown Motors are backed by a 2-year, 24,000-mile warranty. With all of this on the plate, it makes its virtually a no-brainer when it comes to making the decision whether a person should build their own motor or buy one of these killer Motown motors.
The motor arrived via truck freight to our shop and came complete carb to pan with its own dyno sheet to show that it has been run. Our particular 427 managed 520 hp and 530 ft-lbs of torque. After plugging the motor data into our computer simulator, the GT55 should manage 0-60 mph in the low-4-second range, run mid-12s in the quarter, and top out at just under 160 mph. Considering the aerodynamic challenges that a '55 Chevy faces, the Bill Mitchell Motown motor will be a true miracle worker!