Starting My 5.3 Swap....Computer Questions?

[Ford Assassin]

Hey guys, recently I bought a 1969 C10 SWB Fleetside as another project, but one that I could start with my [soon to be] wife (she loves working on my toys). Anyway, I want something dependable and something that wouldn't kill my mpg and still have a decent amount HP/TQ. After weighing cost (among other things) I decided on swapping in a 5.3 Vortec engine.

Today I bought a complete setup (engine, computer, harness, MAF, etc) from a rolled low mileage 2004 Burb. I already have the engine mounting handled, so that's out of the way. I will prob end up running full length headers too since it looks like I would have to trim too much of the stock frame to make the stock manifolds work.

I did not buy a transmission since I have 28" tall tires and 3.08 rear gears. That means the TH350 tranny I have will be bolted to the 5.3.

I did several searches and found that the stock computer will need to be tweaked to work for me (I figured). I have read that the un-used inputs can be 'edited' off the computer and I have also read something about 'pinning'? I made a list of things that would not be used in my case, but I am fuzzy on how this is done..... (please explain both).

-VATS
-EGR
-Speedo input from trans
-Rear O2 sensors (no cats)

Okay, lay it on me. What else do I need? Any help is thanked in advance.

Thanks guys!!