I think everyone was confused at to what screw you meant.
It appears you were talking about one of the pipe hanger bolts. Lots of them strip when trying to come apart, they actually break loose inside the pipe where there is no way to get to them.
Mine did the same thing, I ground the head of the bolt off and just slipped the pipe hangers off and installed the hangers on the Tpipes. Been there, done that.
Glad you got it off, now on to them ThunderPipes and get some face relaxing cream, you'll be needing it soon.
