Rear Differential Cover Heavy Duty 1963-77 and 1978-79
The "Rear Differential Cover" is a known weak area of the Corvette the rear cover supports the entire weight of the Corvette on hard launches and corners. The red heavy duty cover is 6 to 7 pounds heavier than the stock black cover compare them in the picture see how much thicker the edge of red casting is compared to the black rear cover. Note the picture of the two covers lying flat on the table you can easily see the heavier webbing ( u shaped area) of the red rear cover compared to the stock black rear cover. Covers are shipped as bare casting.
Please note in some rare cases. It has come to our attention that the heavy duty cover with heavy ribbing in the casting plus the use of silicon instead of a gasket for sealing the rear end. May result with interfere with the movement of the Corvette rear end. Before installing installing the rear end in the Corvette turn the pinion and make sure there is no interference between the cover, bearing cap or ring gear. The best way to resolve this is to simply grind some clearance in the rear cover. This will not compromise the covers effectiveness.
Steve @ Dragvette Products