don't forget about the 100lbs you shave with the aluminum block though

all things being equal, two turbos are the way to go (I think). they make gobs of HP/TQ, have EXCILENT drivability, and still keep good gas mileage. I like my LS1 (in the F-body) and if the 5.3 liter blows up/wears out down the road I will probubly swap in an LS1 but to swap a perfectly good 5.3 costs too much for what you get.