Don just read this whole thread tonight. Glad to hear you found the cause of the noise.
When I was building my engine I had a heck of a time finding the right pulley setup, but it seemed March performance was my only choice. The problems I had were they under or over drive pulleys trying to get extra power out of the engine, since I used a high flow water pump, I didn't want to overdrive the water pump with a small pulley, and vice versa under drive the alternator. I think ultimately there are just fewer choices for us Ford guys. I ended up using the stock pulley on the 460.
I'll have to take a look at Runne-Rite so I can see if they have any options that will work on the 460! Hope everything goes smooth from here on out.