You were right on the money with the G-Force sports and Tread Separation. We had a tread separation at our last Race. Its true I probably ran them above 165 mph for about 15 miles before it let go, but the entire shoulder came off one of the back tires, that has never been run on the front.
The good thing was that the main tread was still intact... so the whole tread didn't separate, just the shoulder...and I drove another 105 miles averaging 140 mph on what was left of the tire. I'm glad I didn't stop and look, because we ended up winning the class and finished 4th out of 155 cars. If I had seen the damage, no way would I have kept going.
I'll try to post a picture tonight.