Doctor Diff- manufacturer seems to depend on the ratio and carrier. Not sure of the country of origin on some of them, some (like the 3.55/741) seem to be his own brand. Could always ask him. Not a bad price, either.
I can confirm this. I bought a set of 3.55 gears from him about a year ago and he shipped them with the inside styrofoam but not the outside box? Almost like he didn't want me to know what brand they were?
I'm breaking them in now, but have no complaints so far. I'm going from 2.76 gears to 3.55 BIG difference.