USA standard gears?

Has anyone heard of or had any experience with USA Standard gears? I'm interested in swapping out the 3.07 for a 3.73 or 3.90 and came across this:
http://cgi.ebay.com/ebaymotors/NEW-...014QQitemZ330149229224QQrdZ1QQsspagenameZWD1V

I dont know if they are USA standard gears when there is a pic of the Yukon gears. IF they are Yukons, the arent bad gears, I run 4.56's in my D30, they were easy to setup, and havent gave me any problems. I don't think they make 3.90 gears for a D30, unless you have a 2wd.

I do have a 2wd and the guy told me the master install kit was Yukon, but the gears were "USA Standard" gears. He has 100% rating, but that's feedback from transactions, not from using the parts he sells.

I'm pretty sure there is better deal out there on gears. I know Yukon gears aren't gonna cost that much.