Wow. Lot's and lot's of ideas. Thank you all.

I did try heat but only with propane. I did the PB blaster a dozen times. No allen screw. I had ground off a little bit to be sure it wasn't mushroomed.

Sooooo. It's part of the pulley? Well duh. That would makes sense. I will try that tomorrow.

Again Thanks to everyone!

1946 Chevy Half Ton
('56 235, '86 T5, '79 Camaro Z28 rear end, working on the '85 Jaguar XJ6 IFS)
1976 Margay Panther X, MC91B