OK,I'm in contact with a possible vendor who is telling me they may have some of the 3.42/3.91 gear sets for the 'O' type 12 bolt rear axles. They are like the other after market gear sets that have been available. They are the thick ring gear so they can be used in a 3 series carrier. They also said there might be a possibility of making the 3.42 gear sets for the 4 series carrier if demand is high enough. This is an expensive deal for them and I told them that the 3.42 would probably be the gear of choice over the 3.91. If they do indeed have some of the thick ring gear sets,the ring gear can be ground to make them work in a 4 series carrier. I'm needing feedback on this and as soon as they take stock of what they have of the gear sets,I'll let ya'll know.

Mike

***************UPDATE******************

The vendor says they have the gear sets in 3.42 & 3.91 O Type 12 bolt rear axles. They are $340 each set. I do not know if they are the 3 or 4 series carrier gears. They also said they may have the posi units available also. I'm doing this to help the guys needing the gears as I do not have a use for them. You can contact them @

FABCRAFT in S. LAKE TX.
ATTN: DAVE 817-421-0242

 

don't buy anything u have to grind to fit

 

I'm not buying anything,I'm just trying to help the guys looking for gears. Besides,nothing wrong with grinding anything that's done correctly. There's precision grinding equipment with magnetic tables. I've talked to guys who ground the aftermarket gear sets with no problem. If you have any info I'm not aware of,please let me know.

Thanks

 

Thanks for sharing this info. I will point out that your use of 3 series & 4 series terms is odd & confusing when it comes to the Type O 12 bolt. The carrier that you refer to as the "4 series" houses the OEM 3.42 & 3.91 gears as well as the dealer installed 4.33, 4.66 & 5.00 gear sets. Your "3 series" carrier only houses 3.08 & 3.23 gear sets.

 

These are the generally accepted definitions.

Note to Mike: I'd be more interested in 3.91s, if you're taking a poll. In fact, 4.33s with a 200-4R would be even better.

 

It's going to be a long shot to begin with because it's a pricey deal. I know from selling used complete 12 bolt axles it's harder to sell the 3.91 vs the 3.42. It could be if the demand is high enough,both the 3.42 & 3.91 would be possible. It takes about 75-80 sets to make it feasible according to the vendor.

 

I'd be interested in a set of 3:42's. Keep me posted.

 

x2

 

Can't imagine demand being an issue.
Lots of people looking for 3.42's for the big carrier including myself.
If interested parties would contact this vendor, it would give him a real feel for the demand.
DO you mind saying who it is?

 

I can't say right now as they asked me to wait and see what they have in stock. When they confirm I will post their info. I'm not in the middle,I'm just trying to help the guys who need gear sets.

 

This is great news about the O Type gears. They're great rear ends but limited or no gear availability has long been their drawback.
I'm probably in the minority of O-Type owners as I have multiple rears and gear sets in 3.23, 3.42, and 3.90 ratios. I started back in the 70s with 2.56 rears and over the years learned to grab any rear with a decent ratio.

 

im looking for a posi323 342 o type rear 12 bolt case with 10 bolt innerds

 

TTT Info added

 

I've talked with and bought stuff from Brad at Fabcraft. Good guy.