ok guys i used search and couldn't find anything and don't know what to type for...so .. i just took my b16 tranny out cause of it grinding..now..when i put the gsr tranny on..for some reason when i reverse then step on the clutch it jerk forward. what is it? can it be bad transmission , pressure plate, shift linkage?? need help guys.. everytime i reverse i try to step on the clutch to go to neutral but for some reason it jump forward when i step on the clutch...

 

Ok, to be more clear,

You put the car into reverse (that funtion is fine)
You reverse (no problems)
When you go to engage the clutch again to stop reversing, the car then jumps forward?

If that is the case, I would have to assume something in the trans is not correct. Something may end up braking, or someone had it apart and didn't line something up correctly.