Is it possible to put 3.07 gears in a Dana 70HD? If so who even makes them?

Just curious to see if my old rig can pu tout some decent numbers. The rig is a C6 and can't get much above 12.5 mpg at 60mph. Just want to do some testing and not really planning to ever pull with it. I got another pickup and a V8 jeep for the samll stuff.

Any input?

Thad

 

David is running 3.08's in his, but I think he has a 10.25 rear instead of the 70.....no idea what make though.

What gearing do you have now?

 

3.73...

Thad

 

If you're not going to haul with it, then maybe another axle might be a good option. The D61 semi-float was available with 3.08 gears from the factory, I think in vans mostly.

 

True but finding one near me is another story...

Thad

 

If you find one from a van, it can be any van up to the brand new ones, 2011, they still use our old bolt patern for the rims....


But I don't think the frames are the same width on the vans than the trucks.


I can measure tomorrow though.

 

well let know my 84 was with 307 great fuel miles but towing it would take me 7 miles get up speed with a 8,000 lb trailer behined me and would suck up lot fuel but this was 6.9

 

I have 3.55s w/ 35's. From what i can get out of the gear calculator that is give or take the same as 3.08s. I wouldnt race anyone uphill, but it still pulled fine. Used to tow a home made car trailer with a 3600 lb car on it with 200lbs worth of tools just fine up and down hills. Turbo on there now definately didnt hurt anything. With the turbo on there now, there is no way i would consider shorter gears, in fact as ive said before, im looking forward to the 37s with the 3.55s

Especially since you have an auto, and no OD, i wouldnt worry about taller gears, whether towing or not.

 

Yeah, I have no doubt about the rig being able to drive without issue with 3.07's....

Just need to know if I can get 3.07's in this axle or not.

Thad

 

Didn't DAVE85 have something like 3.08's in his?

 

Yes he does.

 

3.08's even for the sterling 10.25 are no longer in production and haven't been now for a few years.
your primary focus should be swapping to an OD trans.either with the much more advanced E40D auto or the manual ZF5.
the problem with the C6 isn't just it's lack of an OD gear,but that it never makes a direct connection with the engine.this was "passable" when fuel was a buck a gallon,but even then wasn't much to brag about.now at $4 per gallon.............
fuel economy will raise greatly,and for a DD will pay for itself in short order.