Diesel rear axle help.

[78C10BigTen]

Unknown if they are related but my 12 bolt gov bomb had all the posi pieces taken out and was just running open wheni purchased it... i swapped a cheap clutch type posi into a 10 bolt with my axles and its running great.

 

[rpcraft]

I do not know tis 100 % but I think technically you can take some of the gov lock parts out and it essentially functions as a open diff, not optimal if you need a locking diff but better than doing a major amount of work on something you most likely want to change out in the future. Doing that will allow you to go get a diff gasket and fill it with oil and keep on trucking (just clean it out well before you do). Whatever you did to break it will probably occur again so I would start looking for a 14 bolt Full floater and having that should prevent breakage in the future.

 

[77 K20]

That sucks about your rear axle... I'd say your best route now is to find a full floater 14 bolt. Quite a few will have 4.10 gears, or if you can find a military 14 bolt then it will have 4.56 gears with a detroit locker.

Your 3.73 gears wouldn't have been a good match for you new larger tires (whatever size you are going to run).

Yes, driveshaft length will be different, but they needed to be modified anyway for your 6" lift.

A detroit isn't the smoothest easiest thing do daily drive- in winter it can fish tail around corners. I've gotten used to it and daily drove mine for a lot of years.

Detroits are probably the cheapest option, but if you want 100% smooth and don't even know it is there then get an Eaton Truetrac. I have one in the front axle, and talked my buddy into putting one into the rear of his Silverado. He loves it.

 

[77 K20]

A quick search found a K30 rear end:

https://boston.craigslist.org/nos/pts/d/rockport-84-chevy-gm/6857387517.html

It has the 3.73 gears so you don't have to re-gear the front if that is your decision. But a one ton rear end has different shock mounts and the spring perches are in a different spot. They would have to be cut off and new ones added in the correct spot.

Or:

Using car-part.com Tom's Used Parts in CT has a 1976 C20 rear axle complete with 4.10 gears for $250. They offer shipping.

http://www.tomsusedautoparts.com/?q=inventory

 

[HotRodPC]

I get it, it's a Diesel so you want to keep the RPMs down as low as possible. But you really need to know 100% what you are going to do since it is a gutless Diesel. If you're going with a 6 lift, there's more wind drag. If you're going to 35's there's more lift, more weight to spin and you better be considering 4.10's. But since it's a 4x4 that means you need to find 2 axles in 4.10's front and rear. That 9.5 isn't all that bad and plenty strong enough for a 6.2. I think it's the Gov Lock Locking Diff, I'd try to avoid. Find you another 9.5 with 3.73's in an open diff and get it running again since finances are in the ditch at the moment. You can add a lunchbox locker later to an open without having to remove and reset up the R&P. Sometimes you gotta do things in a particular to make them happen or they don't happen at all. Ask me how I know. Or anyone else here for that matter that knows all the awesome projects I've had and not to get very far on a single damn one of them.

 

[4WDKC]

Are you going to take this off road or is it a highigh crawler?