I swapped out the 4:56 pumpkin in my 53 3/4 ton 3600 to 4:11s bolt in swap, now if this works back to 1942 I don't have a clue. Measure the bolt pattern on your 3/4 ton rear and compare to 50s-60s trucks. IF you are in luck re. size and bolt pattern then you need to locate a late 60s 3/4 ton that came stock with an automatic trans (make sure it's 4:11).
If your truck has 6 lug hubs none of the above applies. This info is for 8 lug trucks.
BTW, I'm running a 6 lug truck rear end out of a 1966 Chev pickup in my 1946 half ton. Gears are 3:08 and lots more ratios can be found in these years.
Best of luck
Last edited by JiMerit Boltr#43; 04/16/2019 5:53 PM.
