If it is a 3 speed it would have a column shifter. You may think first gear is granny low because the rear gears are 4.57's. The standard 3 speed 1st gear is 2.94 and the 4 speed is 7.06 - that's a granny. There was a warner HD trans offered in earlier trucks that had a 3.17 first gear. I'm not sure if it was available in 65. It has the overall size of a 4 speed.
Fred
