http://americanlemans.com/primary1.p...=paddock|14262
This is the ALMS web site.
GT1 was eliminated because no one wanted to play heads up with the old C5R's and C6R's. The Alms made "competition adjustments" to the corvettes using weight penalties and restricting motor output. Eventually there was not much that could be done to "level" the playing field in GT1 so corvette racing was tired of being frustrated and they agreed to a new class, GT1 with new rules.
I'm not gonna BS and say I know the new rules as I lost intense interest because the level playing field don't work too well in competition; somebody has to get the short end of the stick. 5+ L V12's do not = 7 L V8's.
I think the Caddy's are in the Rolex Series if I'm not mistaken.....although I could be wrong on that. I know that there is no factory corvette effort in Rolex. Camaros and GTO's before the Camaros and before that it was the early CTS's. The vettes were all privateers like LG racing. Those guys had no chance against the factory Porsche & BMW & Mazda teams.