Factory are 1.82 and 1.76.
The 1.76 is the more desirable because the carrier / planetary is way stronger..........stock.
The way to tell them apart without opening one up is the length of the input shaft. I forget the exact length but if my memory still works , the 1.82 is about 1/8th inch longer.
you're close. 1.82 input shaft is 12 5/8 inches long, and the 1.76 shaft is 12 7/8 inches.