i just bought a new shift knob but its a thread on and my car obviously doesn't have a threaded shifter. does anyone know what size die i will need to tap it? the knob came with a few thread adapters so the thread count won't be a problem.

Pick an adapter and match up the die to it. It aint hard.

no its not hard. never claimed it was. but i don't know the diameter of the shifter. a 3/8 die won't fit a 5/8 shifter or the other way around. thats what i was asking not "what size is ideal" . and seeing as how i don't have a tap and die set and don't want to go and pay upwards of $75-100 for a good set for one application, its easier to just ask someone who might know.