going for the mileage with gears

[greg_a_morton]

my 2000ps daily driver with 10.5 rear has 3.73s and I was told that you could put 10.25 gears in it with the right bearings. I have read in some books that some early f250s had 3.08s in them. Is this correct and does any body have a good set of gears in that range? I could cruise at 1700rpm and when I needed to pull I could just stay in 4th gear!!!

 

[flatlander]

Might want to do some more research whether or not the 3.08 came in a 10.25 rear end. My 84 has that gear but is a dana 61which has virtually no aftermarket parts.

 

[Diesile]

Interesting. Never heard of a D61. I've got the '86 D60 w/3.54. I know that with those gears and the diesel T-19 the space between gears is a little too big empty. Never could figure out why Detroit can not get that simple chore right.
T-19 is definitely a rock though.

 

[greg_a_morton]

At one time there was a guy on ebay selling what he said was 3.08 gears for 10.25 10.5 and he stated that the gears could be used in a 10.5 with 10.25 bearings. I did not buy at that time because of money issues and the gears were $239. with new bearings and seals it came to about $350 and thats not including labor.

 

[typ4]

Dana 61's showed up in fords and some dodge vans and as far as I know only will accept 3.08 or 3.30 gears, the pinion is farther from the ring and standard d 60 gears dont mesh when you install them.

 

[BigRigTech]

I haven't had mine up to highway speeds yet but I can say that the 3.55's I just put in are going to help my mileage.....I just to have to correct my speedo to find out how much....

 

[flatlander]

Interesting. Never heard of a D61. I've got the '86 D60 w/3.54. I know that with those gears and the diesel T-19 the space between gears is a little too big empty. Never could figure out why Detroit can not get that simple chore right.
T-19 is definitely a rock though.

I hadn't either. Every indicator on the rear end said it was a D60, so I bought 3.73's only to find out when we started tearing it apart that I did not have a D60. After doing a little digging, I found a set of 4.10's for the D61 which I didn't want, and could not find a LS of locker for it. So I took a D60 out of a beater 75 Ford and build it instead. Just need to get it insalled.

If you want a 3.07 rear, I'll make you a good deal.

 

[greg_a_morton]

thanks but I just want to swap gears in mine. Dont want to have to change wheels or go to old style brakes.

 

[Diesile]

Flatlander; Thanks it would be tempting! Problem is I'm a 4x4 and I've already got a 'spring' project. The 'ole original 6.9 (300k) is making a non-original noises so I'm going to put the 'spare' I've been sitting on (a 7.3 IDI Turbo '94) in and
rebuild the 6.9 assuming it makes it to spring and hasn't ground itself to junk
(metal in the filter) by then. Not happy about that but shoT happens.

 

[Cat_Rebel]

You can get 3.08s for a 10.25 rear. Dave Witmer uses them on his truck, not good for an auto. You really need a stick to use it.

 

[Diesile]

Whose got 'em Cat Rebel??

 

[greg_a_morton]

Do you know if his was factory or were he got them?