i have a 1991 z28 with a 305 tpi auto, and a 1988 firebird Formula 350 with a 305 tbi 5 speed, and i wanted to know if the 5 speed would mount up to the tpi engine, and if i needed the harness out of the camaro, or what i would need to make it work, i have searched the forums and havn't found what im looking for, would appreiciate the help.

The 5-speed will mount to the auto engine. You will need to install a pilot bearing in the crank first.

You will need at least the ECM to engine harness.

pilot bearings are also called throw out bearings am i correct?, if so the 5- speed should already have one

No, the pilot bearing is what the snout of the transmission input shaft fits into in the back of the crankshaft to stabilize the input shaft. The throw-out bearing is what releases the clutch pressure plate when you step on the clutch pedal.

The T5 will have the throw-out bearing as part of the transmission/clutch, but the pilot bearing stays in the crankshaft (unless you get a puller and remove it). They're only a few bucks at any parts store or GM dealer, just get a new one.

Same could be said about the throw-out bearing - they're only a few bucks, they are a wear item, not a bad idea to just put in a new one while easily accessible.