3.91 gears?

[Henrietta]

Was reading a post and when I went to completeoffroad's site I saw the 3.91 gears. Is anyone running these. I know most people go with 4.11 or 4.56...is this a good middle of the road gear for both on and off highway usage? What would you put in the front?

 

[wildbill]

;D ;D ;D Gears go with tire size. 3:50 stock to about 31's and 4:11 is good for 33:12.50x15's and if you go bigger then 4;56's hope this helps as for 3:91 a mustang typ gear not used in the bronco. Bronco 4x4 used 3:50 , 4:11 , 4:56 and Im not sure what they ran in the 2 wheel drive. Bill %)

 

[Broncobowsher]

Whatever gear you get for the rear, you need to match in the front.

The options for the 44 are a lot more limiting then the 9” out back. I know that there was a 4.27 gear for the 44 and you can get a 4.30 for the 9” That would work.

The 4.10 and 4.56 are common gears. the common gears are more affordable then the off gear ratios. I remember seeing some odd gear sets costing around $400 while the standard 4.10 is only $150. So I would consider cost to be a deciding factor.

 

[Bronchole]

Also i beleive that the 4.27 are not available for the HP44.

 

[Broncobowsher]

There are a lot of thing that are not available in certain axles. The 9" just happens to accept just about everything. Now were you wanting a 3.89, 3.90 or 3.91? I believe that they are all available through the aftermarket. If you want to get real nutty, I found 9" gears that go into the 7+:1 range.

 

[Unregistered]

The point I was making is nearly the same as yours except that the available selection is even narrower for HP44. If I remeber correctly it jumps from 4.11 to 4.56.

 

[4byford]

It isn't that much of a difference; for commonality and cost 4.09 front D44/4.11 rear 9" would be a better choice and the difference in RPMs and driveability are negligible.
If a guy really wants to do it, he could use 3.89/3.91 rear gears and put a Dana 44 3.92 R&P in front (low pinion diffs only).