Opinions on rear gears

33 IMP · Sep 7, 2019

I have contemplated changing out the 4.10s in my dana, but the 3.54 didn't seem to be enough of a change to be worthwhile. Now Dr. Diff has 3.23s available. I may have to rethink.
To the op, just my humble opinion. 220° or less duration at .050, go with 2.94. Its a cruiser. More than 220, id use 3.23.

Cranky · Sep 7, 2019

33 IMP said:
I have contemplated changing out the 4.10s in my dana, but the 3.54 didn't seem to be enough of a change to be worthwhile. Now Dr. Diff has 3.23s available. I may have to rethink.
To the op, just my humble opinion. 220° or less duration at .050, go with 2.94. Its a cruiser. More than 220, id use 3.23.

Going from 3.54 to 3.23 isn't worth the hassle. Haven't read all the posts here but a larger tire would be much cheaper and easier. The gear change is less than 10% difference. Why not just go with more gear and bite the bullet and install a Gear Vendor's OD and have the best of both worlds?

33 IMP · Sep 7, 2019

@Cranky, it's an original A12 car, so it's got factory 4.10. I think 3.23 would be enough of a change to warrant the work, i nust dont know if i want to mess with it. And its wearing 29" tall tires now. 3600+rpm at freeway speeds.

Cranky · Sep 7, 2019

Ok, for some reason (doh) I was stinking 3.54 to 3.23..... :realcrazy:

BSB67 · Sep 7, 2019

33 IMP said:
To the op, just my humble opinion. 220° or less duration at .050, go with 2.94. Its a cruiser. More than 220, id use 3.23.

Probably a decent rule. I've used a 222° @ 0.050 on a 112°
LSA and 2.94 gear. Ran just fine. That motor did have a decent compression ratio and blew about 190 psi on the gauge, which would make a difference too.

Bobby Sixkiller · Sep 8, 2019

3.23 is probably a great all around ratio. Not too tall. Not too short. IMO. Now if you had overdrive I’d stay with 4.10 but gear vendor is really expensive. My Roadrunner runs 2550 ish at 65 with 3.23 and still peppy enough around town

RJRENTON · Sep 8, 2019

Not sure if the 4.10 carrier can be used with the 3.23 ratio. Is the 3.23 ratio ring gear made thinner to accommodate the pinion gear size (39 tooth R vs 12 tooth P = 3.2 ratio)? Maybe not the correct tooth count Just curious....
Bob Renton

33 IMP · Sep 8, 2019

I think 3.54 and 4.10 dana use the same carrier. The 4.56 and lower carrier is different. Maybe it's 4.30 on down.

RJRENTON · Sep 8, 2019

Yes.....I was enquiring about the 3.23 ratio fitting on the series 3 carrier. Usually when using a 4.30 ratio and higher on a Dana 60 series 3 carrier, a spacer is placed under the ring gear, along with longer ring gear bolts. Or a series 5 carrier is used...thicket carrier ring gear mounting flange. I was curious about IF a thinner 3.23 ratio ring gear is needed if using a Dr Diff gear set?
Bob Renton

Opinions on rear gears

33 IMP

FBBO Gold Member

Cranky

Banned Henchman #27

33 IMP

FBBO Gold Member

Cranky

Banned Henchman #27

BSB67

Well-Known Member

Bobby Sixkiller

Well-Known Member

RJRENTON

FBBO Gold Member

33 IMP

FBBO Gold Member

RJRENTON

FBBO Gold Member

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