Cracked rubber shock bushing

[68 Sport Satellite]

This rubber shock bushing had less than 2000 miles on it. Why would this happen? Edelbrock IAS shocks before I switched to Bilsteins. Only thing I can figure is when I reassembled all the front suspension with the new motor I may have over tightened the nut. Can you over tighten these?

 

[mopar 3 B]

Would not think so. The nut should bottom no the threads first.There should be a stamped metal lock nut above the steel nut on the shock stud. I see your is missing.