SUCCESS!
Ahh that wonderful feeling you get after fighting with a task for a long time and then you finally get it! I still have to swap the bulbs over but today the truck started and ran with an alternator!
Here is the "custom" bracket I made. It works just as good as the spendy ones you can buy.
As you can see it moves the alternator back to line up the pully and moves it over a little bit. The alternator I got was trying to occupy the same real estate as the tab on the generator bracket so I just moved the bracket back, ran my threaded rod through, and viola!
I haven't wired it up yet but I started it with the alternator on to make sure it wouldn't throw the belt. WOW does it start great with 12V!
Here is the finished thing!
I'm really excited and proud. This was my first real fabrication to solve a problem. It was small but it took me a long time to figure out and get right. Now I'm ready for the next one. I do only have one regret. The alternator wires come out at the 3 o'clock position so they point to the block. If someone else does this like me get one with the wires coming out at the 9 o'clock position. And yes I am using a 3 wire GM alternator with the internal regulator.
I saw the brackets to buy anywhere from $60 to $90. Mine cost less than $20.