Royceflo,
I had a similar problem. Here is a thought....
Take a look at the wiring harness from the alternator to the first junction into the main harness. It unplugs right behind the valve cover. It's only about 4" long. After unraveling the tape you may find burnt and shorted wires wear they have been wearing against the valve cover. I found 3 wires that had gotten really hot and melted together with the alternator wire. One was the oil guage causing it to flicker at all rpms, the other was a coil wire. The wire enamel had melted off and were allowing them to short against each other.
The fix is to save the modular connector and buy some new brass connectors and wire. It took about 2 hours to crimp and soilder everything up and get it re-wraped and installed. A little conveluted tubing wouldn't hurt either to keep the abbrassion down. I used some dipped/coated clamps as standoffs from the valve cover bolts to hold the wire bundle. That way it will not rub against any metal. With the new wire bundle everything works fine now.
On the alternator, take it to the "Rebuilder". It is a business that just rebuilds starters and alternators. They carry all the stuff to rebuild them.
You can find them sometimes near Marina's or near industrial areas. I am not sure if the high amp chrome units Summit and Jeg's sells are new or not. Maybe Dan can give us an update on them. He should know.
