Gentlemen--Thanks for feedback on both. You are correct that the standard ratio for this truck was 4.57 or 5.14 per my manuals. My nephew and I checked the ratio and it came out over 6 so unsure if it was swapped out or if we just miss counted. The new rear end did come out of a 1970 GMC 3/4 ton(saw the title) and is definitely a positrac. It does not have a drop out 3rd member so must be the Spicer/Dana rear end. I have not been able to clean it up enough to see if it has any identifying markings, but sure that it will not work without swapping my entire rear end. I have new Huck brakes, drums turned, brake lines, etc, so just wanting to swap out the differential on current truck. Sooner or later something will come up, but many places scrapped out old stuff back when scrap metal prices were high. I have a couple of people looking so expect to find one soon. Thanks for the help and advice while learning about this old truck. Thanks
Willie
