What is a 10 bolt rearend?

A 10-bolt rearend refers to a type of rear axle assembly, primarily used in General Motors vehicles, characterized by its differential cover held in place by ten bolts. It's not a description of its strength or capacity, but rather its identifying feature. While often associated with passenger cars, some trucks and heavier-duty applications also utilized 10-bolt rearends, though stronger alternatives were usually preferred for those uses. The strength of a specific 10-bolt rearend varies greatly depending on the vehicle and year of manufacture. Some are quite durable, while others are relatively weak.