Just got the car, It shifts fine in all the gears but when I put it into reverse And slowly let out the clutch, it pops outta reverse, sometimes when it does this it seems to be getting stuck into 2 gears as it will not move. There is quite a bit of play in the shifter I dont know if buying a pro 5.0 will fix it or are there internal tranny issues. I'll be dropping in a 383 soon and I'm not sure if I'm going 6 speed yet or having the tranny built. If i go 6 speed dont wanna waste the cash on the shifter for the t5. Just wanna fix the problem and drive until the stroker is done.
The car is a 1991 RS with a 305 and T5 thanks for any help.

 

When that happens in the other gears it usually means the synchros are bad, but reverse isnt synchronized. I would bet on a chipped tooth or something similar on the reverse gear. There isnt much you can do to build up a T5 to make it strong enough, so just save up for the T56.