Need advice on fixing broken rocker stud on Big Block..

[bs46488]

A little more info....

I don't see any marks or contact on the rollers. Here is a pic of the damaged one, you can see some silver on the bottom that looks like the threads.



The rocker studs are 7/16 and just shy of 2"

The previous owner bought these rockers from a marine shop for $120, but no part numbers.

The cam is a Crower 01243, intake 284 with a .541 lift. Exhaust is 290 at .517 lift. The cam card says based on 1.7 rockers, but I can't identify mine.

I can not tell any info on the springs in the head