Originally Posted by Bill Harris
An interchangable spigot is probably the easiest way. You might be able to have a 97mm spigot on one side and a 99mm on the other side and flip the jig over.
It is very do-able to drill by hand. If you are skilled and lucky, the hole (and repaired stud) are nice and square. If you have an off-day, or marginal skills, the stud is wonky. I've seen poorly repaired studs fail and then you have one and only one chance to re-repair it. For the average or below-average home mechanic, it's better to have help, and the drilling jig probably boosts the chance of success.
True that, but some like the idea of making their own tools.
Thanks Bill, the description of drilling by hand is exactly what I thought it was. Also like your idea of one spigot on each side.
But here's a thing. Do you really need to use the spigot to center the tool? There should only be one thread hole to repair? Most of the time I think. So use the good threads to center the tool, no spigot. Might/might not work?