Hurst Billet Plus Shifter with a Mach I/Bullitt Knob?

I have a Hurst Billet Plus shifter on my 89 GT. The stock knob fits fine. I'd like to swap the knob out for an OEM Mach I/Bullitt knob. Will this work? If not, anyone know of a repro Mach I/Bullitt knob that will fit it?

I will admit I got a supposedly OEM Mach I/Bullitt knob off eBay. The inner diameter of the tube on the knob was too small to make it to the threads. I'm starting to think it's a repro since it didn't have any Ford box with it. If it is original can I just drill the tube out a bit to clear the thicker diameter handle? It is supposed to fit an original T5 shifter handle and my OEM GT handle fits the Hurst handle so I don't get it....

OK...found my old stock shifter. The Hurst shifter handle has a larger diameter all the way to the threads while the stock one is thinner far enough below the threads to clear the Bullitt knob, then gets thicker. Now that I know the threads are good, maybe I can figure something out.