Ok so here is a basic timeline:

1) Transmission goes on, car starts, goes into all gears and drives fine

2) Find out transmission casing is stripped at the mount so i get it switched with another gsr casing

3) Put transmission back on correctly and everything is lined up and perfect, BUT, now only gears 1,2, and 4 go in. 3rd, 5th, and reverse gears no longer go in.

I really cannot think of any problems that could have caused this, i watched the guy switch the casings and he didnt touch any of the internals of the transmission. If you guys could please help me out it would be greatly appreciated.

 

something might not have lined up correctly in the casing when going on?

 

sounds like one or more of your shift forks arent working correctly. always shift a tranny through all the gears BEFORE you re-install the trans into the car, just my 2c