Guys, you have all been most helpful here. When I concluded my test, the voltage across the battery had dropped to 13.2v and I have to assume it continued to drop back to 12.8 as everything is brand new and I have no starting issues. I'll take a new voltage reading upon my return to northern Michigan (were the truck is) over the holidays. Since I was not involved with any of my truck's wiring I can't be sure that it is correct. Sounds like the best plan for me is to study up on the correct wiring for my alternator and start there before junk the alternator installed with the engine rebuild.
Merry Christmas to all!
Pistol Pete
