I have 1 1970 F350 that seems to have hybrid differential, I guess. It is a Dana 60 built in 1968. The problem is the rear inner pinion bearing is 4.1" diameter race like a Dana 70 but the bore of the bearing is basic 1.625 of the Dana 60. The 4.1" bearing at 1.7+ is way too big for the pinion. Can't find a bearing yet that resolves this. The cover was loose when I got it and full of water. So I know somebody was in there before. If I went with a Dana70 ring and pinion will it need a new carrier as well?

 

Welcome Bob ISTP. Because "someone has been in there " clean and look at the 4 corners of carrier where the axel Tubes come in. On Spicer/ Dana axels there would be 44 or 60 or 70 cast in one of the corners and you will know what you have, a 60 or a 70 series. Hopefully that will set you in the right direction to finding the parts you need. All bearing cups and cones should have #'s on them, the #'s would be industry not Dana/Spicer. Not sure BUT, F-350's with dual rear wheels would have 70 series, POSSIBLY single rear wheel trucks might have 60 series. Hope all helps you. Cap

 

My '67 F350, SRW, has a Dana 70 from the factory, I believe all the F350's did. I think the only difference between SRW and the duallies was the wheels they bolted on, as mine came with duals on the rear. The brakes are the same and interchange between the two. Check the door tag, decoding that will tell you what came factory. Also check for the Bill Of Materials number on the housing, will tell you exactly what you have.