Lately it's been hard to shift into 3rd gear for some reason, all the other gears go in fine. It doesn't grind or anything, just is really stiff feeling. I've got a Pro 5.0 shifter installed as well.
Clutch feels good and the resevoir is full.

 

Your synchros are shot...well for the 2-3 shift anyhow. This was the last thing to go....after my brearings.....you need a rebuild .The longer you wait ....the more it costs

 

I agree, sounds like a synchro ring going bad.
While you're replacing this one, I'd take care of the rest, it saves you the hassle later, when something else goes. Just MHO.

 

Thanks for the info.
Now I have to decide if I want to pull the T5 out of my 90 and slap it into the 88 and see if it works since I do not know the current condition of the 90's T5 or just rebuild the 90 T5 and put that into the 88 and then rebuild the 88 T5 and put that into the 90.