78 -79 Rear Differential 3.70 gears OJ code

[Shawn's 78]

WTB 78 -79 Rear Differential 3.70 gears OJ code

Howdy all!
I'm looking for a good usable (bolt in) 78-79 rear differential with 3.70 gears; OJ code.
Anyone have one for sale or a lead on where I can find one?
Thanks
Shawn

 

[GTR1999]

I'll take a look at my cores to see. Is there a reason you want a 78-79 diff other then the date coding? They had some issues with those years but they can easily can be corrected.I'm doing a 78 308 diff now in fact.
I do have a nice 78 rear cover.

 

[Shawn's 78]

Gary,
What kind of issues did the 78-79 years have? Wasn't aware of any.
Why those years? 1) I have a 78 and if i'm correct, it would be a direct bolt in as the yoke sizes are the same. 2) without having to rebuild one, my thought was a lower miles 3.70 differential would be a better option than an original 60's comparable for a direct bolt on. 3) there's cost savings for a 3.70 from those years than say one from the earlier years.
That all said, if I can pick up one (original) or have one made, it needs to be within my budget.
Your thoughts?
Shawn

 

[GTR1999]

Shawn
The late C3 run had issues with soft side yokes, RG bolts backing out due in part to a switch to flanged head bolts no loctite or lockwashers, snowflake clutches that broke under load, and the diff cover for the spring change.
Finding a good 370 diff may be a challenge as most were beatup in 4 spd cars. Any 65-79 diff will work in your car, there were different issues over the years. The 78-79 housings were pretty good as were the posi cases and spiders.
Now building or buying an exchange is a different story, most are basic builds which are ok. some are better then others,some are pretty cheaply done as well. I would rebuild yours adding all the correct parts for your application but your budget may limit that option as a true HP custom diff is going to cost more then any exchange unit.

 

[GTR1999]

I have a ready to bolt in 336 posi. It has new seals and side yokes,no core,you p/u shipping & crate cost. Diff is $500.

 

[Shawn's 78]

That's what I have now. Since the majority of my driving is cruising, I'll take the trade off of a bit higher rpm on the freeway with the 3.70.

 

[GTR1999]

Ok it's all I have right now. I can build you one but no 370 or 373 ready to go.

 

[hotmtrsports]

Gtr1999