4 spd Installation tricks
Perfect clutch alignment is necessary. A good tool is required or even better is an old input shaft. Also, make sure the crank is drilled to accept a 4 speed trans and that the input shaft fits the pilot bushing or newer style bearing. Last thing is to get the trans up there and ready to go the last inches and put it in gear, slide a yoke on the main shaft so you can turn it a bit to get the spline to match the clutch.
Good luck, hopefully you are have someone to help. It also helps a lot if you are not trying to do this while the car is on jackstands, lying on a greasy driveway like I just got done doing.