Im taking the approach of "drive it now and do whatever it takes while you save up for what you want".
So if you have a motor chillin - slap it in and beat the snot out of it while you get the monies for that LSA you want.
Hell - a $500 JY 5.3 with a monster cam and head work will net you nearly 500 flywheel ponies. And that's no slouch. And think of how much money you'll have saved over buying that LS3.
http://www.superchevy.com/technical/...k_build_part2/