I removed my GT3 seats and put in stock seats. They slide up and down properly as they are bolted in. However, they are both stuck forward as they are not tilting back. Can anyone please help with this situation.

 

You most likely tilted the seats forward to get to the mounting screws while you were removing them. You can hit the seat tilt handle toward the top of the seat and you think it will actuate based on the sound. However, the seat has to have power for the mechanism to retract and then tilt back. Did you plug the oem seats back in. Make sure the seat belt lock has not fallen forward and pinched the seat.