I know its not a ls7 but I put a c5r 427 in my truck and love it. It ran a 12.14 first time out n/a. I have it in the shop having spray put on it now and hope to make a n2o pass next weekend.

 

I like the smog and warrenty facts of the LS7, the price is the killer.
Granted you dont get a warrenty as good as a LS7 but, I would preffer a built 6.0.
Its been said before (I think), you can by or build a pretty potent 6.0 with tranny for less.