Let's see. Where to begin?
Well the motor is a resealed 360 FE with cleaned headers and I guess we can start by listing the various problems:
1. Starter drive is shot. Get a new, high quality remanufactured starter. If you have headers, you may have starter overheating issues as the heat sink from the headers into the starter Do Bad Things to your starter.
2. You need a tuneup, including probably a carb rebuild and a check of engine vacuum to see if you have a leak. Timing is probably a big part of the problem here, as well as a well worn, dirty carb.
3. Barfing gas is different than leaking. If it's overflowing gas from the fuel vents, then you have a sticking inlet valve/float valve. I have this on a 302 that I use infrequently at best. If it's leaking gas as the carb is used, chances are this truck sat long enough to let gas erode the rubber seals, gaskets, etc. and you need a rebuild kit.
4. replace all of your belts. Fan, PS pump, whatever. They're old, varnished up, and that's the source of the squeal.