Lots of play in the gearbox in all gears?
 

The gearbox in my 89' SAE is all loose even when in gear. It's to the point where if I park it in 1st and someone gets in it's possible to confuse it to be in neutral (makes for some funny/scary moments when someone else trys to start it)! I replaced 1 cup bushing as when I took the car out of its long slumber and cleaned up the shift boot I found the shredded bushing in the bottom of the shifter. The play is still there the one I replaced was a greyish one that you can see the top of it if you lift the shift boot up.
Any ideas?

have you looked at your coupler?

Had a GF like that once.....but I agree the coupler is the first place to look.

Funny thing is I bought the coupler w/ cup bushing and lost it. Was hoping it wouldn't cause problems down the road.
Guess I might aswell replace the O-Rings while I'm down there.

O'rings?