88 k2500 14 bolt rear end and 89 k1500 rear end

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Kawikid

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Never mind found the answer

The desireable axle is the 6 lug version found in OBS half ton 4x4/Z71s, OBS 4x4 2500 LD 6 lug trucks, and OBS 3/4 Ton 6 lug Vans. The only difference between the truck and van axles is perch width and bumpstop location. Also note, the OBS 2wd 2500 LD 6 lug truck has the 14SF as well, but it is 3" narrower (65" vs 68") and would be a favorable swap for a 2wd OBS truck as the axle width would be the same.

The Z71/4x4 2500 LD axle is a direct swap into any OBS truck with the exception of needing a 1330-1350 crossover u-joint (Precision #448). If the Z71 axle is swapped into a NBS, then the spring perches will need to moved outward and you will need the 3R-1350 crossover u-joint (Precision #447). The OBS perch width is 47" and the NBS perch width is 49".

If the Van axle is used, then you will need to relocate the perches regardless of what truck it is going on and you will need the appropriate U-joint according to whether or not you have an OBS or NBS.

The NBS SUV disk brakes can be swapped onto the 14 SF if 2.5" backing plate flange spacers are used. The axle flange OD (the part of the axle shaft that the wheel studs are pressed into) will have to be turned down 3/16" to fit the disks. I want to say that the measurement for the backing plate flange spacer is the same if using the truck disks as well. You will still need to turn down the axle flange OD the same amount if you are using the NBS truck disks.

If for some reason you absolutely cannot find the crossover U-joint, the 10 bolt Yoke will bolt up to this axle, but you would not be taking advantage of the larger yoke that is already on the 14 SF.

Axle Tube Dia: 3-3/8" (Same as 14FF)
Axle Shaft Dia: 1-3/8" at the splines, 1-3/4" at the bearing
WMS-WMS: 68" for Z71, 4x4 2500 LD and Van 6 Lug

I have set up 3.73s, 4.10s, and 4.56 gears in this axle. The pinion shims used which resulted in good looking patterns are as follows:

3.73s - .035"
4.10s - .037"
4.56s - .036"
 
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