We also swapped the ring-and-pinion gears in the rear Dana 35 and front Dana 30 axles. Since we were replacing the stock 3.73 gears with a set of 4.56 gears, however, we also required a new low-ratio carrier for the front Dana 30 since we exceeded the carrier break point with the lower gears. The carrier break point of the Dana 30 case is 3.54 and down and 3.73 and up. In most instances that you require a new carrier due to a gear change, you should consider installing a locker or limited-slip differential at the same time. Aftermarket lockers and LSDs are typically stronger than a stock carrier, and you won't have to pay for a second installation when you eventually decide you need a front locker.
For installation of the Yukon Gear & Axle and OX-USA components, we sought assistance from the qualified crew at T&J Performance Center in Orange, California. The job was easily tackled in a day's time and included a thorough inspection of the old parts and the axlehousings to ensure proper fitment and operation. T&J also provided a new Dana 30 carrier and a Dana 35 pinion yoke to complete the installation.
The OX diff cover is forged steel and includes a mount for the shifter arm and shifter cable. | 
A well-designed shifter assembly is provided with each OX Locker. The shifter is crafted from steel and features two shift positions for locker engagement and disengagement. A pull lever locks the shifter in each position so accidental engagement won't be an issue. | 
The material construction of the Yukon alloy axleshafts offers much greater strength than the stock shafts. |
Yukon Gear & Axle also provided a set of 4.56 gears for the Dana 30 and Dana 35 axles. | 
Here, the old fluid was drained from the Dana 35 rear axle. Since we had recently acquired the vehicle, we were unsure of how old the fluid was, but it was extremely filthy and gritty. | 
We had sustained some damage to the differential that wasn't so apparent before disassembly. A few of the spider gears were noticeably cracked, which had left small chips of metal to cycle through the assembly. |