USA Standard Gear ZGK2005 Master Install Kit for GM Rear Differential - 8.5

The USA Standard Gear ZGK2005 is a comprehensive master installation kit designed for GM 8.5" rear differentials. This complete kit provides everything needed for a professional differential rebuild, including a premium ring and pinion gear set with 4.88 ratio, installation components, and a 30-spline positraction unit.

Kit Includes:

• 4.88 ratio ring and pinion gear set for GM 8.5" rear axle
• Complete pinion installation kit with bearings, shims, and crush sleeve
• 30-spline posi (limited slip differential unit)
• Axle bearings and seals for both sides
• Pinion seal and carrier shims
• Pinion nut and marking compound

Key Features:

• Precision-machined ring and pinion gears for quiet operation and long service life
• OEM-quality bearings and seals ensure proper fitment
• Complete kit eliminates multiple part orders and ensures component compatibility
• 30-spline posi unit improves traction in low-grip conditions
• Ideal for restoration projects, performance upgrades, or worn differential replacement

This master kit is compatible with GM 8.5" 10-bolt rear axles commonly found in 1971-2013 GM trucks, SUVs, and passenger cars. The 4.88 gear ratio is an excellent choice for improved acceleration, larger tire fitment, and towing performance. USA Standard Gear manufactures all gearing products to meet or exceed OEM specifications for durability and quiet operation.