They have been putting the lq9 6.0 in the ecsb's since 04' they just kept it quiet. I just bought an 05' with the 6.0. The option is called Silverado limited performance package and i think you could only get factory 20's with it. In 04 i know that youcould get factry 20's as a silverado limited appearance package with a 5.3, but the dealers didnt have to many of those so chances are that if you see a chevy with factory 20's then it most likely has the 6.0 lq9. Yes they are offering the 6.0 lq9 for 06' both chevrolet and GMC are. All you have to do is call the dealer. Also next year the SS will be 2wd with the 6.0/4l85e. It will be considerably cheaper like 35k or so. Just thought this might give you some more info
EATIN' FORDS AND TUNDRAS
RIP 2005 VHO ecsb 6.0HO, Comp Cam, Nelson Tune, OBX LT's.