Oh yeah, I have LS1 fans on mine, too. I guess I didn't realize they were only 12" in diameter. How wide of a radiator is the fan shroud on the '05? I have a 34" radiator and it would be nice to have a shroud that covered the whole thing. My LS1 only heats up when it idles for too long. If I rev the engine up to about 1500 rpm for a few seconds the water temp drops back down to about 180. I wonder why it doesn't circulate water good at idle.