sounds like its coming from the drive line somewhere, mainly in the rear. tried pulling the rear brake drums but the big 3/4 ton ones were seized/stuck on the hubs.
I've got a 1984 K20 truck. I've had it for a little over a year and I just started having an issue of when I accelerate it squeaks and squeals real loud. It has the 4 speed and 208 transfer. I've replaced the rear u-joint and checked the fluids in the rear end, transfer, and transmission. I...