69 c20 10 bolt rear end making noise. Rebuild or replace?

[bambbrose]

Hi everyone.

New here and new to trucks actually. I've spent most of my time working on modern FWD vehicles so this thing is a big learning experience for me.


Anyway, I have a 69 c20 custom camper that I just picked up for $650. The 350 in it runs perfect and is in excellent shape, but it has a 10 bolt rear end that is whining on deceleration and sometimes making a clicking noise. It has signs of leaking and I had to add a lot of fluid to it to fill it back up. It is a coil spring/trailing arm suspension truck.

My ultimate goals for this truck are to build an excellent daily driver. I plan on converting it to a shortbed, and swapping in a 5.3 (or 4.8) gen III eventually, and lowering ~4" all around, but that won't be until I finish my education (~18 months from now). Ambitious I know, but attainable.

I want to fix the rear end properly and set it up for my future goals so I don't have to mess with it down the road, but my budget currently is less than around $750 for fixing this problem (other things on the truck need attention as well).

I want to get away from the 8 lug, and go 5 lug disc/drum in the long run.

Here are my questions for all you experts.

What gearing is in my truck stock (4.10?)? and what gearing is available for the 10 bolt?

Is the 10 bolt worth rebuilding? or should I just look for a good used 12 bolt or something else?

If I were to keep the 10 bolt, can I just swap axles/brakes/hubs for the 5 lug setup in the future?

Is it likely that damage was caused to the housing from running low on fluid for a while?

Is $750 budget doable or should I wait and save?

and lastly, I want to be able to get around 20mpg or better with my 5.3/4L60E setup, so gearing is very important. I won't be towing or drag racing this truck, just cruising and hauling stuff on occasion. What gearing would you recommend?


I apologize if these are redundant questions or this is in the wrong section. I did a brief search, but due to my lack of time and the fact that this problem needs to get fixed sooner than later I figured I just ask for your help.

Thanks

[grayw0lf]

Personally, I wouldn't bother rebuilding a GM 10 bolt. Are you sure its a GM Factory 10 bolt & not a Dana variety? These trucks never came stock w/ GM 10 bolts.

[Sinister]

My '69 C-20 has an Eaton HO52 rearend. I think if I remember correctly it has 10 bolts on the cover. I'll have to go out and count them...

[Shyguy]

I wouldn't try to rebuild the 10 bolt rear end.

I would swap it out for a 12 bolt '71 or newer with 5 bolt anxles and 3.08 instead. They are pretty easy to find and not real expensive.

Danny

[bambbrose]

Hey thanks for the help guys. I looked into the 71-72 5 lug axles more and that seems like exactly what I'm looking for, plus its a lot cheaper so I'll have money left over to refresh everything that I get.

Better yet I found some listed in a local junkyard so I just gotta make the trip now.

Thanks again

[67_C-30]

Originally Posted by bambbrose

Hey thanks for the help guys. I looked into the 71-72 5 lug axles more and that seems like exactly what I'm looking for, plus its a lot cheaper so I'll have money left over to refresh everything that I get.

Better yet I found some listed in a local junkyard so I just gotta make the trip now.

Thanks again

I'd look for a 3.73 geared 12 bolt out of a 71-72 truck. You could go with a 3.08 geared rear, but it will be pretty gutless in OD, especially with a 4.8L. 20mpg should still be obtainable with a Gen III and OD with 3.73's.