Allen: What jack has to say is all true. You have a 2R5 and that is where the obstacle is. If you know how to set up a differential you are on the positive side. If not then you will need to find someone to help you.
first A 2R5 will likely not pull gears with a number than 4:27 or at best 4:09. If you had an automatic you could do 3:73 but likely you have a straight 3 speed or maybe a 4 speed transmission.
second your truck without overdrive most likely came with 4:89 or 4:82 gears. The part that holds the ring gear is called the carrier by most people, the parts book calls it the case. Either way the carrier must match the gear so the pinion can fit and drive the ring gear. They are rare but there is one carrier that can be used on 4:09, 4:27, 4:54 and 4:89 gears.
Most likely you will need to decide which gears you want in your differential and buy it with the carrier.
Third you will need to inspect it to see if the spline in the spider gears match the spline of your axle. If you choose a carrier from most older Studebaker cars (with a Dana 44 axle) they will match and you can just install the complete unit with matching pinion in your differential. If not you will need to pull the spider gears from your current unit and place them in the new unit so your axles will fit. Newer Studebaker cars use 19 splines instead of 10.
If you choose parts from a Dana 44 from another manufactures vehicle you may also need to change the spider gears.
Should you wish to pull the complete axle from a 1956 or newer truck remember it is wider than the one in your truck. It will fit with no trouble but your tracking with the front wheels will be wrong and you may wish to obtain a wider front axle. If the system you choose is from a 1956 or newer Studebaker truck the axles will have 19 splines and there is a wider selection of gears to match your axle with no modification.
Posted on Apr 19, 2017, 10:44 PM from IP address 220.127.116.11