i agree the L67 is def the best choice, i just like to see what u guys think. the N* is crap, my mom's had a few in her cadillac's. whenever my pop and i lined up, i'd blow the doors off it, but top end that motor will put up good a fight. they enhale gas though and i mean destroy.
I would love to do an LS1 with an M90 on it. i'm planing it out when this motor (if ever) shits out on me.
as of right now i have no reason to touch my GTX it beats most V8's with mods.