Fits for Chevy 1978-88/ for GMC 1/2 Ton & 3/4 Ton - Front; Fits for Chevy 1977-91 Suburban 4WD - Front JGhyperX offers cast aluminum differential covers for most case design applications. They feature thick gasket rails to resist oil leaks, as well as cast-in ribs for added strength and heat dissipation. Some models include a drain plug and/or filler plug. Choose from Natural Aluminum with machined rib edges, Black Powdercoated with machined rib edges or Highly Polished finishes. These differential covers include a gasket and mounting bolts for a complete installation.