Nasty squeeling noise

[Lippyp]

I drove my truck around my back yard for the fist time in a couple of years, I encountered a problem when I put her into reverse in that I got a horrible metallic squeeling noise from underneath the cab. It seemed to match the engine revs. I have fitted a new high torque mini starter (proform) and I'm wondering if that might be the source, if not could it be down to the transmission (TH350) or something else. Help I have no idea where to start. She moved fine just this horrible loud noise. Brakes were crap but I think thats just because of lack of use, manual drums and new shoes on the back not bedded in. They will be gone through before she goes back on the road and converted to power drums with all new lines, and wheel cylinders and maybe even a new master.

The noise is worrying though as I don't want to screw something up. I don't need to drive her any distance, just out of my yard soon and onto a flatbed/trailer to move her to our new house.

Any suggestions welcomed.