Revolution Gear & Axle GM 10.5" 14 Bolt Full Spool 30SPL 4.10&DN. All Revolution gear sets are made from the highest quality steel and are precision heat treated to OEM specifications, making for the best aftermarket gears available. All Revolution Ring and Pinion sets are backed by an industry leading 2 Year Warranty against defects. Revolution gears are also double, and in some cases triple lapped for flawless setup, smother running and longer life. With products that have been Street, Off Road and race proven for more than a decade, you can count on Revolution Gear & Axle products to be the best aftermarket parts available.