You can take a 3 spd handle and make it into a 4 spd , has to be machined though! No difference ! Would need the t handle piece But wouldn't work vice versa. The nob is the same size and thread in black is correct for a 3spd or 4spd consolette car as the shift pattern is on it! A non consolette car should have the shift pattern on the 4spd nob although I have seen many with consolette and shift pattern nobs.