I believe all 65-69 Mustang/Falcon/Cougar/Fairlane 6 bolt bell housings were for the 157 tooth flywheel. While the Tremec will "bolt up", the input shaft is too long. A 1" thick adapter is needed or the input shaft can be modified.
A forum community dedicated to vintage Ford Mustang owners and enthusiasts. Come join the discussion about restoration, modifications, NOS parts, troubleshooting, VIN codes, and more!