Shift knob threads

Ok, so I know that the thread size for the f-body six speed is 16mm-1.50, I wanted to have an 8 ball shift knob, but the only ones I could find were expensive, so I thought why not just buy a ball and drill and tap it myself. So I bought 3 balls cuz I knew the first one would get screwed up somehow, these didn't cost me much, and then after finding out the size thread, went to napa to find a tap and got one. So today drilled out one of the balls, then went to tap it, got about 1 inch of threads into it, tried it on the car, and it wasn't right. Would start and go down some, then got really stiff, thought wtf. So I matched up the tap and the stick, and they don't match up, wtf? Is the tap wrong, it says 16-1.50 on the tap, or is my stick wierdo. I think that the tap is wrong, what do you guys think?

take the stick off...go to the store and test thread the corresponding die...or even a nut may work.

if its stock it should fit.

could be your hole is wrong

I had a hard time finding anything in a 16mm-1.5 everything was 16mm-2. I finally had to buy a large tap and die set to get the one I needed. Maybe the tap you are useing is a 16mm-2 and they labeled it wrong.

I think that it's labeled wrong, cuz it's a stock shifter with the stock knob, and when I matched up the stick and the tap, the tap doesn't match, I can get the first few threads at either the top or bottom to match up, but then after that they don't. The guy ordered two, a bottoming tap and a regular tap, I have the bottoming one, I'll go back and ask to see the other and take it out in the parking lot and try to match it up with the stick, hopefully that one will be the right one.

Why not just take and get the propper sized nut for the shifter, drill a hole large enough to hold the nut in the 8 ball and just epoxy the nut into the ball so you have metal threads to use instead of plastic? Just an idea. I guess you would have to insert the correct size bolt into the nut to make sure no epoxy gets into threads. May be easier than trying to rely on plastic threads.

very true, I might end up doing that.