Core Shifters Service Bulletins

Hurst references:

Related vendors:

Transmission references:

Tremec 5 speed:

Tremec 6 speed:


  • If you want to see the pitfalls of a trans swap - read the "Hot Rod to the Rescue" article in Hot Rod Magazine issue April 2017 pg 88. The most important points are here-
  • Driveshaft tips to avoid vibrations:
    • Trans & rear axle yoke centerlines should be parallel to each other within 0.5 deg
      • This is hard to do w/ 6 speed in old car without cutting floor or rotating rear axle housing
    • Angle between either yoke and driveshaft should be 0.5-3.0 deg for conventional U-joints
    • Checkout the Tremec Toolbox App to measure driveline angles w/ your smartphone
  • For hydraulic release bearings - checkout Speedway Motors' setup tool to set proper travel range