that's cool that you are using a 5.3... you can pick them up so cheap, and people ran 327s for years! I swapped a 215,000 mile 4 cylinder and junk trans from an S10 straight up for one!
Have you seen the Car Craft article where they did a heads and cam swap on a junkyard 5.3 and got 460+ hp and almost 400 ft. lbs!
http://carcraft.automotive.com/72081...ine/index.html
Good luck with the project... should be a blast to drive!
Kix