Charlie, is yours the kind that has the button inside the distributor and a double nut on the outside? If so, I used to make them by taking a regular screw driver and cutting the middle out of the screwdriver bit about the size of the stud with a hack saw. Its not the prettiest thing I ever made, but it works. I had a socket in an old Snap On 1/4 drive socket set, but I'm not sure I still have it. Its one of those things that stays gone for a while and then reappears.
