Just double checking here

[CknightK10]

Heyy girls!!! So Im planning on doing a crossover steering setup on my truck this summer and because of the fact that I will have to remove one of the knuckles, I have decided to go the extra mile and just re-gear the front while its torn apart. Now up front I just have a stock 10 bolt with 3:73's but I am going to install 4:88's and all new seals and bearings. I am 97% sure Im at 28 spline up front. Correct me if I am wrong, I am not positive but I think I have 30 spline in the rear. It is a 12 bolt 8.875. Out back I will be running 4:88's with a Detroit Tru Trac. Opinions please!! oh and if you can help ensure me that I am 30 spline in the rear that would be great!!

 

[bucket]

I'm not saying you shouldn't re-gear, but just having one knuckle off isn't half of the work involved. It's hard to say for sure on the splines. '85 would be 28 spline in the front BUT, I'm almost positive that it would also be a 10 bolt rear. I've researched it before and it's very confusing, the 12 bolt was phased out in the early 80's but it was still used along side the 10 bolt, based on 2wd/4x4. I don't remember the final year it was used.

Anyway, if you're rear axle was swapped in at some point, there's a very good chance the front was swapped in too. So it's possible you have a 30 spline front.

 

[HotRodPC]

OEM should be 10 bolt rear if its 82 or newer. But that does not mean someone didn't swap a 12 bolt in it.

 

[CknightK10]

I'm not saying you shouldn't re-gear, but just having one knuckle off isn't half of the work involved. It's hard to say for sure on the splines. '85 would be 28 spline in the front BUT, I'm almost positive that it would also be a 10 bolt rear. I've researched it before and it's very confusing, the 12 bolt was phased out in the early 80's but it was still used along side the 10 bolt, based on 2wd/4x4. I don't remember the final year it was used.

Anyway, if you're rear axle was swapped in at some point, there's a very good chance the front was swapped in too. So it's possible you have a 30 spline front.

I have a 12 bolt in rear. The guy who had the truck before me swapped a 12 bolt in the truck. Stock it was a 10 bolt. I know it IS a 12 bolt and I am pretty sure that it is 30 spline but was not positive if ALL truck 12 bolt rear ends were 30 spline. The front is a stock 10 bolt. I know re-gearing is alot of work and that is why I will attempt to do the front myself, because it is not quite as crucial as the rear, which I will pay to have somebody install. Im just trying to save myself a little bit of money, and time here thats why I am doing it this way, since the hubs are going to be taken off anyway, I might as well pull out the axle shafts a bit and get to the gears.

So basically my question is, is there a chance that my rear end is 28 spline

 

[bucket]

I don't think there ever was a 28 spline 12bolt, but I could be wrong.

 

[HotRodPC]

Just a suggestion here Ck??? Do you have a specific reason why you are deadset on 4.88??? Sounds like lotso $$$ to regear to 2 axles. Also you'll likely have to replace the carriers too cuz I think 4.10 is the cut off. 4.10 and taller gears, then 4.56 and lower gears, so to get to 4.88 you'll need to replace carriers too.
How about settling for 4.10 which is the most common in the 14b FF, or get lucky and find a 4.56 set up in the 3/4 - SRW 1 ton with a 14b Full Floater rear and Dana 44 or 10 Bolt already set up with 8 lugs and the matching gear for the rear end. I see sets around here quite frequenlty for $300-$400. Gets you both the 14b FF and D44 or 10bolt front from drum to durm (rotor to rotor). They bolt right in then you are regeared and beefed up for some strength too. Of course they'll be used though, but just for the money you'd spend on new carriers alone, you could have the beefier parts, then rebuild them 1 at a time as funds permit and as they break down or get noisy with new bearings, gears etc. Usually just need new bearings and seals for a rebuild. Rarely do you need need new gears, unless they were ran just way out of tolerance and hammered on the gears. I just think it would be cheaper in the long run, and much beefier for strenght. Of course you'd have to get new wheels too. Just a thought and suggestion. Thats how I intend to regear my 85K10 that is wussy 3.08 gears. I am putting 8 lug axles in it.

 

[Wrecker]

You could get a Dana 44 from a 3/4 ton and swap your outers on keeping your bolt pattern. The 44 is way better than the 10 bolt in my opinion and worth spending a little money on. I say this because I'm assuming your going with some big tires with the 4.88 gearing. Stock and I'd just run the 10 bolt.

 

[HotRodPC]

You could get a Dana 44 from a 3/4 ton and swap your outers on keeping your bolt pattern. The 44 is way better than the 10 bolt in my opinion and worth spending a little money on. I say this because I'm assuming your going with some big tires with the 4.88 gearing. Stock and I'd just run the 10 bolt.

Lots of controversy on the D44 and 10b fronts as to which is stronger. Just curious Wrecker. What makes you think the D44 is way better? I've heard one is stronger than the other in one area, the other is stronger in another.

 

[hirschdalechevy]

I have ran both fronts with 35 and bigger tires , with good hp and have not had to much trouble with either , other than breaking axle joints in both of them.IMO both are good fronts.