Manufactured using permanent mold, magnesium/aluminum alloy castings, each rear includes a heat-treated lower shaft, 4.86 ring and pinion, roller pinion nose bearing, and pinion posi nut. Rears listed include .188" wall centerless ground 2.5" GN axle tubes, 5 x 5" 2.5" GN hubs, .810" wide brake rotors and solid axles. "Max" option Rears include the substitution of a black thermal coated housing, billet rear cover, all REM internals for reduced drag, lightened spool, drilled lower shaft, gun-drilled axles and breather kit.