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Looking for in-stock aftermarket parts to modify or upgrade your 1978 GMC C15 with differentials? At Tunersports.com we carry a huge selection of the top name brand performance differential parts and accessories.
 IN STOCK - LOW YDGGM12T-3-30-1Yukon Dura Grip is a positraction limited slip differential that provides smooth yet aggressive traction, giving you the confidence and performance you need across a wide variety of terrains. The Dura Grip is engineered for long life and is completely rebuildable. Dura Grips are constructed with a h... Yukon Gear Dura Grip Limited Slip Differential for GM 12 Bolt 30 Spl 2.76-3.42 Ratio 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $754.89 |
 IN STOCK YDGGM12T-4-30-1Yukon Dura Grip is a positraction limited slip differential that provides smooth yet aggressive traction, giving you the confidence and performance you need across a wide variety of terrains. The Dura Grip is engineered for long life and is completely rebuildable. Dura Grips are constructed with a h... Yukon Gear Dura Grip Positraction For GM 12 Bolt Car w/ 30 Spline Axles / 3.73+ 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $919.89 |
 IN STOCK - DROPSHIPS SL XP-GM12USA Standard Spartan Locker 12 Bolt GM Spartan Locker Cross Pin 1975-1978 GMC C15 Base / High Sierra / Sierra Classic / Sierra Grande 1977-1978 GMC C15 Heavy Half 1978-1978 GMC C15 Street Coupe $56.89 |