[slomotion]

Esahic, all of the info you've been getting is good, straight stuff from guys who know what they're talking about, but before you go changing up a lot of parts, re-read SS Tim's post #3. You need to know what condition your engine is in before you make any substantial changes. You need a baseline to start with to know what needs to be done first. Do a compression test and write down the numbers. (This is your cylinder and ring condition) Check your oil pressure with a known good gauge. (A general condition of bearings, although not all-inclusive.) Do a leak-down test. (Ring and valve condition.)
If these tests come out within the specs you're good to go with the modifications, but if your foundation isn't sound you'd be much farther ahead putting your $$ into bringing the basic engine up to the best condition possible. These are tough engines, and last a long time, so your chances of having a good one are on your side, but you need the baseline now so you can document which modifications over time- (HEI, headers, 4bbl, etc. etc.) made the biggest difference in performance. You're in a pretty exclusive club! Sixes are cool!