87 conquest 5.9 magnum s475
Still looks like 1/8" to me . I magine how small an allen wrench would be to fit inside a 1/16" plug, would be so small u couldn`t tighten it up w/o breaking or rounding it off. Lots of auto stuff is called wrong according to the plumbing Industry .
Is the outside diameter of those plugs the same as oil gauge copper tubing !!