Be sure to get a 2002 or newer 6L to get the LS1 size crankshaft end. The early models had a longer crank and requires a flat flexplate, not dished. Also, double check the bolt pattern of the flywheel to the converter before it goes in the truck, if you have to rework the holes in the flywheel to mate up to the converter, its so much easier to do out of the vehicle. That or just use the flywheel off the 4.8L engine.