I ended up using a 65" 12 bolt posi from a '69 chevelle ss with 3.73 gears- I went through it before installing it, replaced the bearings, seals, etc... and reset the preload.
It used to be that the 12 bolts were more desirable than the 10 bolts, but I believe that the quality and strength on the 10 bolts improved alot and they are just as strong as a 12 bolt, or stronger.
I've heard over and over again that the real weak link in the gm axels is the c-clip design. However, I've never seen an axel come apart due to c-clip failure. Nonetheless, you can't use c-clip axels in NASCAR without a c-clip eliminator kit.
The ford 9" is a very popular and common axel because it is easy to work on and everywhere. Next time I do one of these trucks I'll find a 9" with disc brakes and then if I don't like the gearing it's easier to change the gears with 9" than GM by far.
