Two possibilities- - - -a timing gear that's rubbing the cover (not likely) or a front main bearing. There's also the possibility that the damper ring on the crankshaft balancer has come adrift and is rubbing the outside of the timing cover. Time for some major surgery, beginning with pulling the balancer. It's a press fit, and will require a T-shaped puller bolted to the balancer to remove it. Once that's done, run the engine for a short time with the balancer off. If the squeal is still there, pull the oil pan and the timing cover and inspect the gears. Yes, the oil pan must come off- - - -the two bottom timing cover bolt heads are through the bottom of the front main bearing cap with the heads inside the oil pan. Yes, there's a good reason for that.
Jerry
