Rear shock length for cv joint driveshafts

[billwill]

I think the hole is D shaped in the spring-abutment plate (the shallow cup thingy that holds the top of the spring.

[rgh0]

The shafts are typically hard chromed to protect the surface and provide a smooth polished surface for the seal and top rod bearing.

The step and D of the shaft is required to locate the top spring cap

cheers
Rohan