hey mike...good thing i left a margin for error in my initial post!
i used m6x1 taper thread zerks in my new beam (dirtydeeds custom built beam). so far they seem to be holding up and lubricating the front end just fine.
after comparing them with an original zerk from an original beam, the original zerks seem to be m8x1 taper thread.
the reason i used the m6x1 zerks is that my tap & die kit doesnt have an m8x1 tap and i remember having trouble trying to find one...so i went m6x1 instead.
both m6x1 and m8x1 taper thread zerks can be purchased at crappy tire!
hope that helps, sorry for the mixup! let me know if you need to borrow a tap!