Weld stud size for leaf spring

The Dart has struck again! My 1967 Dodge Dart 270, that is. I'm installing new leaf springs from ESPO. The forward mount (which holds the pivot bolt) on both sides of the vehicle had a weld stud snap on me. An either/or dilemma now faces me.

Either

(a) it is safe enough to drill out the stud and weld a new one in (in which case, what size am I looking for?),

or

(b) I need to buy a new mount (in which case, where can I buy a stock one?)

Ideas? Thanks ahead of time for your help!

View attachment 1715240613
They are splined. Pressed in. Should b able to knock it out with a hammer. I may have some good ones in a junk hanger...