1982 Malibu power steering pully

OK, I'm stuck. Well, the pully is. I have a puller, but when I screw the bolt, the two grips just come off the groove on the pully. I've torched it and pb blasted it and it's still stuck on. Any help?

Try a better quality puller. The jaws should not move or flex and should not jump out of the grooves.