New from American Powertrain – the Pro-Fit 6-Speed System for 1968-82 C3 Corvettes. This complete kit is built for easy installation for smooth as silk shifts. See more details below.

Official Release:

American Powertrain, the world’s largest TREMEC dealer, is now introducing the next generation Pro-Fit 6-speed system for 1968-82 C3 Corvettes. The system looks like the original 4-speed transmission with the correct shifter position in the factory console.

Designed as a complete kit, it features an American Powertrain customized TREMEC® MAGNUM 6-speed transmission that offers a choice of four different gear ratio combinations; all that will shift smooth as silk, a new crossmember, driveshaft, trans mount, offset shifter mechanism, calibrated speedo drive, Speedo cable, reverse light harness, 6-speed shift pattern plate, and mounting hardware. The transmission is rated at 700 lb./ft. and will shift up to 7,000 RPM.

American Powertrain’s DOM steel driveshaft, built with an exclusive billet face flange yoke, will make installation a five minute job, even in the narrow tunnel of a classic Vette. Options are available to upgrade to an aluminum, chromoly or carbon fiber driveshaft.

The price for the 6-speed Pro-Fit Kit for C3 Corvettes starts at $4,395, transmission included. Bellhousing is sold separately. All Pro-Fit kits are covered by American Powertrain’s two year warranty and includes free extended hours tech support.


  • Offers a choice of four different gear ratio combinations
  • Shifts smooth as silk
  • Designed as a complete kit