Try Gandrud Chevrolet in Wisconsin. At one time they were matching the GM rebates on the LS motors. Not sure if the rebates are still available, but it is worth a try. They also price matched on some other parts I bought, accessory drive, oil pan, etc. They are very helpful.
call Sean Carter@SMC Performance (248) 276-0483
hes a great guy with alot of knowledge on ls motors and can hook you up on about any engine or package that you want.