Hello, it's me again. After several months on the back burner this project is coming back around. I ordered what I thought was the correct Dana 70 ring and pinion gear set from Summit. When my dad went to install it, the ring gear was about 1/8" thicker than the old one. Pictured are the numbers found on the old gear and the new one. Here is a link to the Summit product I ordered: https://www.summitracing.com/parts/sdh-706999-4x

Can anyone spot an obvious mistake? Can anyone identify the old ring gear by the numbers?

Any help is greatly appreciated! Thank you in advance.

 

Ring gear: 31711 // Pinion gear: 31710 = C6TZ-4209-H .. Ring & Pinion Kit 4.10-1 .. Parts list # 96 = 1966 F350 Dana 70. This R & P kit can also be used on 1967/77's, but the companion flange is also required.

Ring gear: 31711 // Pinion gear: 34550 =C7TZ-4209-B .. Ring & Pinion Kit 4.10-1 .. Parts list #'s 176 & 177 = 1967/77 F350 Dana 70.

Ring gear: 34840 // Pinion gear: 34550 = D8TZ-4209-C .. Ring & Pinion Kit 4.10-1 .. Parts list #'s 176 & 177 = 1978/79 F350 Dana 70.