Yeup, you're right. My only concern now is the height of the engines - I know the 6.1 has that "supercharger looking" intake manifold which is pretty tall. That diagram tells me that the 5.7 is 6 inches taller than the LS1 which is recommended for the GTM kitcar. If the 6.1 is taller than the 5.7, I could start to run into some fitment issues - or at least ruin my rear-view capabilities, which might not be wise for a frequent-if-not-daily driver.
Oddly enough, the 6.1 and the LS1 are the exact same length, which tells me that the difference must lie in the stroke of each engine.
Thanks for the help!
Jeff