Doctor Diff 8 3/4 Sure Grip
Bought this one (Powr-lok, which is the one you’re referring to?) and a set of 4.10’s from him. He said the Motive Gear and Richmond gear sets are the same manufacturer. Only the box may be different, I’m using a 10 spline pinion and he mentioned 10 splines will be Richmond, although it may be in a Motive box, iirc. Basically makes no difference what the name on the box is. Pretty sure they’re made in Italy. Use the Ford additive and weight lube he recommends if you can find it, and good to go. Only very very rarely, (on first trip out somewhere) making a sharp turn I get a little clunk from the Powr-lok but again, very rarely and only once then there’s no noise. Spend the extra time to get as perfect patterns as you can when setting up the gears
