I had the same prob with my friends Toyota truck. We ended up having to take a little propane torch to the shifter to lossen the lock-tite that was holding the knob on. Take the biggest set of vicegrip you have and clamp down on the knob, then heat the shifter arm just below the knob while twisting with the vice grips. Viola.
I´ve got a 87 egt too and I am going to replace my shifter knob with a chrome and blue one. It is attached to the shift boot so you have to remove the center console first. (a haynes shop manual will help, I have one) then there will be four screws that hold the boot to the floor pan. If the knob is stuck on good you will probably have to take the whold shift lever off so you don´t bend it or anything. because you have to clamp a pair of big vise grip pliers to the knob and pull really hard!!(80 lbs of force) But the shifter on my 87 egt is already worn out the the locktite is not holding at all. so I am just going to pull mine off easily.
I hope it helped.