A Body Spindle Swaps?

I am trying to help a friend without a computer-

He has a 72-73 Duster which had 9" drums, slant 6 and a 7-1/4" rear (I am told). He wants to switch to the larger bolt pattern and disc brakes. He has already bought a 8-3/4" rear, and the SSBC disc kit. However, the kit requires 10" spindles.

Do the 10" spindles have to come from an A body, or are there any other things that will work? Like later B, M or F spindles?

Thanks-

here is the information. This debate has been going on for years.

http://www.bigblockdart.com/techpages/spindles.shtml

The A body 10" drum spindle is an A body only part, '65-'72 are the same.