[ElGracho]

I have the mr gasket shifter in my 84. It's junk. The gates are way too loose and you can move the shifter out of gear without actually shifting the transmission. No amount of adjustment will fix it and my shifter isn't worn out.

The hurst mastershift is the way to go. It's way more expensive but worth it. The installation kit for our trucks is no longer available, but I got one on Ebay. The installation kits that are still available can also be modified to work.

The hole in the floor is straightforward once the shifter is mounted. Mounting the shifter to the trans is a little more complex with all the different mounting holes. There will be several positions on the trans that the shifter can go and almost get each gear, but probably only one that will work properly. Some trial and error (or good pictures from someone with the same trans and shifter) will be needed.