Shock Link (thread size)

[Charles Reese]

Have a set (4) original shock links. Took a lot of kroil/breaker bar strength to remove the end plugs. Would like to ‘chase’ the threads inside the open end of the links before replacing the plugs (may use repros as the slots in the originals are now pretty buggered up). Can someone please advise what size tap/die I need to accomplish this. My 7/8” NF tap is a little too big for this purpose ... 3/4" seems too loose.

Thanks!