Awful Screeching/Squeeling belt noise please help!
 

I have replaced the idler pulley and belt and my tension is good. So whats next? The water pump? How can I check to see if it is my pump? And if it is, what is it like to replace it?

Do you have air conditioning? I have had a air cond pump seize up before causing the same conditions you are talking about. I just unplugged the thing and the squeal went away. Water pumps go bad but I have never seen one tighten up rotation enough to cause what you are experiencing. Usually they loosen up as the bearing wears out and make a rattling noise and there is what is called a "weep hole" on the underside of the pump behind the pulley. If is is weeping the bearing is bad causing the seal to be ate up. The pump can be turned with the belt off. If it turns smoothly with some mild resistance and not weeping the pump is still good. If you do have to change the pump the fan is reverse threads. Use liberal "anti-seize"when putting everything back together.
R

Leave the belt off and fire it up for a second or two...does it still squeal?

no noise at all with the belt off but I noticed that my power steering pulley is kind of difficult to turn and it has about an 1/8" or so of play back and forth on the shaft. no play otherwise though. not sure what to do next. I'm thinking to get a Gatorback belt and if that doesn't do it then it's goin to the shop because I ve had enough of this noise!!!

might be time to replace the power steering pump, mine had to be changed before it hit 80k miles.

alternator bearings?

steering pump...
 

did it have any play in it? was it hard to turn?

dont think so...
 

Definitely not the alt, its the smoothest running pulley on this rig...

gatorback belt or motorcraft belt?

Doesnt matter, it doesnt sound like the belt is your problem...