Boneyard, what did this TPI come off from? If you need I can get you a wire diagram for the computer an other sensors if you would like.
Are you going to buy the painless harness or cut and modify yours? I cut and modified my harness for my LT1 and had no problems, you just need to know what you are going to use and not use (as far as sensors go).
Good luck and keep us posted, and post some pictures.
I may be installing the same set up onto my 1988 C2500 truck this fall.