Stock Shift Knob With Aftermarket Shifter

No that part will not help you. It is only meant for use with aftermarket knobs that have the correct thread size and are intended to fit the factory shifter such as http://www.americanmuscle.com/mb-tribar-shiftknob-0510-black.html. It is strictly for appearance. The factory knob has a different thread and will not fit a Hurst shifter. The only way to make it fit is to re-tap the knob or re-thread the shifter arm.

Your welcome. The shifter arm and the knob use different size threads so to make it work you have to change the thread on one of them. To do that you need a tap and die kit such as this:http://www.homedepot.com/p/TEKTON-Metric-Tap-and-Die-Set-39-Piece-7559/205544445. The pieces in the kit that look like drill bits are called taps. They would be used to re-tap or change the threads on the female part, in this case the shifter knob. The flat pieces with the crosses in them are dies they are used re-thread or change the threads on the male part which is the shifter. You wouldn't need to buy the entire kit, you should be able to just get the size you need or have a repair shop do it. Most will have a tap and die kit. If it were me I would re-thread the shifter arm. It will likely be easier, plus if later you decide that you don't like or want the factory knob anymore there are a bunch of aftermarket knobs designed for the factory arm that would then fit.
Its your car so it should be how you want it but it seems like a lot of effort for little gain but if you hate the Hurst knob,or love the factory knob that much as far as I know that is the only way to make it fit. Maybe some else knows something I don't and can help.

The stock shifter uses a 12mm X 1.25 Thread Pattern