I have been looking for Dana 60 gears and it seems almost all of them are made offshore. According to Dana Spicer's web site their gears are made in the U.S.A. so I will probably get a set of 5.13's and see how it goes. I don't think they are like pro gears used to be. If I have time I may get them cryo'd and polished. That should help them live. I'm not sure how they would last in a Super Stock application but it might be worth a try.
http://www.dennysdriveshaft.com/c872...gear_sets.html