steedapwr351

Hello, my name is mike and i am having transmission trouble with my 1987 for mustang gt. I had a new motor and a new cobra clutch installed in my car and the stock transmission went up so i had my brother-in-law put a tremec transmission in it that come out of a 2000 mustang 6cly. when we try to start the car with the clutch pushed in and the car in gear it rolls and will not start if he puts the car in nutral and pushes the clutch in the car will start and not roll but it is very hard to put the car in gear can you please help