I have a 1984 CJ7 that was living a dormant life in my garage for the last 3 years.  After replacing the carborator and the battery cable it came to life.  However, it will not shift into gear.  For some reason the clutch is not releasing.  If I start the truck in 1st it wants to run.  There is a mechanical clutch and I have done some adjustments, but it won't release.  Do I need a new clutch?  Thanks!!!  

More than likely your release bearing is fried after sitting dormant. Either way you will be there to fix the clutch as well. The bearing is cheap. I would do the pilot as well. Quick check to let you know where you stand is to check while the 7 is not running shift through the gears of the transmission with out using the clutch. You should be able to feel the stick engage each gear. If not you may simply need to check the bushing in the shifter. If there is no binding I believe I am right.  

Put it in first gear, push in the clutch and have somebody pull the jeep with another vehicle. Ignition key in unlock position (so you can steer) but not in the on position. You don't want to jump start it.

Sometimes the friction disc can stick/corrode and not release from the pressure plate and flywheel. They don't stick much, but sometimes it's enough that it will still spin the tranny, and when in neutral does not provide much resistance.  

ftgiles:
Put it in first gear, push in the clutch and have somebody pull the jeep with another vehicle. Ignition key in unlock position (so you can steer) but not in the on position. You don't want to jump start it.

Sometimes the friction disc can stick/corrode and not release from the pressure plate and flywheel. They don't stick much, but sometimes it's enough that it will still spin the tranny, and when in neutral does not provide much resistance.

Good thinking ftgiles. I didn't think of that.