....and last but not least, after HRL's suggestion, Check the water pump when you have the belt off. Sounds to me like you may have a water pump trying to lock up??????
Sometime ago had one that squealed on occasions and being young and dumb I just figured it was due to the fast RPM changes I was always putting it through...but yep, water pump. I figured it out when the belt did nothing but slip and smoke with the pump locked up!
