other than the motor/trans, you want the harness "un-cut", if you have to cut, make sure you don't have any wires that are the same color, if so, cut them at different spots, so the harness can be mended. you want the axle stubs that come out of the trans, save the whole axle assy b/c some swaps can use different parts of the axle. The ECM/PCM should be attached to the harness, so grab that too. When I pull a motor from the yard I grab the above stuff. Also get the A/C line from the car, you can sent both the Fiero and GP hoses off to have them made into one good assy so you can have A/C when done, also, remove the portion of the hard A/C line that has the green wire/sensor on it. You don't need the power steering pump as you will prob be redoing the pulley system if you go low alt route.
as for the mileage, when I pull a motor from the yard, I take the engine down to the block/crank. You can get a kit w/ all the gaskets, O rings and misc for cheap. I also get all new sensors, timing chain and oil pump. Remove the heads for new head gaskets, its good to clean it all up anyway. You may want to install new springs/rockers/lifters and push rods if you find an issue, if not a good clean and soak in oil is a must. Put the motor on a stand, flip it remove the pan and check the bottom end for wear. if your cylinders are in good shape you may not need to go any further, just clean it up, put all new gaskets/hardware in it and run it.
If you have not done this type of overhaul before, make sure to have a bunch of zip lock baggies, and sharpies. Bag and label everything. Take pic's with your phone and have a lot of rags too. Its actually kind of fun.
Rob
[This message has been edited by qwikgta (edited 03-30-2020).]
