Garr,
I posted information regarding the seal installation tool purely as a reference to help me (and others) determine how the seal is located in the axle tube. One point I overlooked in providing this type of information is that often times an OE seal features a larger diameter flange that seats against the edge of the axle tube to control the depth of the seal. This may be why these tools suggest the seal should be flush with the axle tube edge. The seals I just removed were installed by a ring & pinion shop when they installed my Chrysler 4.11 gears so, I never saw the original seals to know if they were of the same design as my previous and current National 8835S, which does not feature an external flange as a positive stop for the axle tube edge. I had no intention of purchasing the C-4076-B to install my seals. The 1-13/16" socket works perfectly for this purpose.
I also checked the existing gap between the inside lip of the metal seal housing and the outer lip of the axle shaft bearing race. I used my 2 mm allen key so the comments that the seal should be seated against the bearing cup are consistent with the seal being slightly recessed within the axle tube and the inner diameter tube chamfer being visible with my previous set of 8835S seals. I could easily insert the 2 mm key (0.78") but, could not translate it parallel to the axle tube length so the 2 mm/.78" is a good estimate for the gap currently between my seal housing and bearing race.
Rick