COAN TH350 Competition Trans.W/6in Tail Shaft. Coan Engineering played a major role in introducing the first transbrakes for the Powerglide, TH400, and TH350 transmissions, now a standard in the industry. Coan Engineering also developed the use of steel stators in its maximum performance torque converters to withstand the rigors of extreme horsepower. Coan Engineering is one of the few companies to offer the design of steel stators necessary for the seven inch torque converter used by many of today's class racers