Highway gears for a Dana 60?!

[pettybird]

           

There's one more wrinkle to this story that not many people know about: 


Dana actually came out with a little-used "Dana 61" casting just for the purpose of fitting a taller gear into their D60 diff design.  I don't think it was every really low even then, but I think it got them down into the 3.23-ish range or something.

     

The Dana 61 was used in the "front" axles of 89' to early 90's Dodge 4wd diesel 727 automatic trucks. I beleive the gear ratio was 3.08. The rear axle was a Dana 70. This ratio was dropped when the automatic overdrive came out.

I have often thought it would be a nice setup to put these axles in our '91 Dodge diesel with a 5 speed manual overdrive to get better highway mileage in place of the 3.54's.

so would the gears fit?

[mopar_nut_440_6]

What decision did you come to?

I am in the same boat 4.10 gears in my Dana but was considering going to my 3.54's but may still want a higher gear set. I was thinking of the passon OD kit in my 4 speed.

[WingCharger]

I am a bit curious too.

[mopar_nut_440_6]

Ok, I called Passon and talked with Jamie. Very nice guy and super informative.

His kit to convert a 18 spline A833 is $1695.00 USD. Bolt right in no machining required just change the 3-4 shift rod as it will need to be longer! Apparently have these behind engines with up to 900 horse and no failures to date!

The gear ratios are as follows:

• 2.66
• 1.59
• 1.0
• 0.8

With 4.10's the final ratio in 4th gear is 3.28 and with 3.54's is an awesome 2.83.

If I run a 27560R15 tire which is approximately 28" tall the top speed at a meager 6000 RPM is 152 MPH with 4.10's and 176 MPH with 3.54's!

With 3.54's 6300 RPM = 185 MPH
With 4.10's 6500 RPM = 165 MPH

This seems to be the answer as I can leave my 4.10's in, launch hard on the strip, factory look, do not need to cut the floor pan, cheaper than a 5 speed or OD and still have decent highway speeds and "some" economy! 2400 RPM at 60 MPH  with 4.10's!

Cheers,