OK guys, I have searched over the forums, and if this issue has been addressed, Please let me know. My son has a 1986 F250 XLT Lariat with a 351W, AC and Automatic. It has approx 150K miles. Recently, he complained the engine was whining and squealing at High RPM.
I looked at the belts, and replaced. I went through several process of elimination attempts to verify the squealing was coming from the Power Stearing Belt/Pulley. I had tried different belt tensions to try to eliminate.

After my help, or lack thereof. he got a wild hair and changed the pump. The squeal is still there. Sometimes at start-up others once he gets the engine to 28-30,000 RPM. The belt alignment is clean and straight. My only guess is the Pulley/Sheave is worn on the inside. If I run a finger inside, there is a subtle groove worn into the metal. Is this a likely cause for "Belt Squeal"? I really do not like to use belt dressing, but the kid did and it stops for a few minutes when he uses it. Once it gets hot. I think it evaporates. but it has left the belt sticky to the touch.

Is there a easy cure for the problem. I am not sure changing the Pulley would make it stop. Plus I am having a hard time locating a "NEW" one. A junkyard could work, but it may be just as worn.

Any guidance would be appreciated. Coles DAD