um...will u should know its the same motor but with different specs to reach the higher hp numbers. u should also know the ls1 motor in the Z28's are way underrated and hit corvette numbers rather frequently, more than GM cares to admit. the ls1 in the Z28 are just as potent as the ones in the c5's. now about the L S 6 (for some reason the board will not let me say is together) ....that would be an interesting swap to do, but i think the ls1 is just as capable.
dont both corvette and Z28's share the t-56 tranny? i beleive they do, the only difference is the shifter sits right on the tranny in the Z28, and in the corvette it doesnt, so it uses a shifter cable, which isnt as reliable i remember hearing as it tends to break when used for racing. any1 feel free to correct me if im wrong on anything.
www.ls1.com is a great place to learn more about the ls1.