By 1967 Triumph were enjoying great success with the bike, especially in the US, here is a brochure for the years US models.
The Bonneville T.T. Special was the hot rod of the range, built as a full on Racer, High Compression Racing Pistons, High Lift Cams, no lights and bigger Carbs were the main items that differed from the standard T120R Bonneville.
Many say the TR6 from 1967 was one of the best Triumphs to ride with it's easy to maintain single Carburetor. The TR6C was the off road version sold with E.T. Ignition and Trials Tires.