Thanks for all the input. This group is such a great resource. The car is a late model Camaro that has mostly metric fasteners (and holes) from the factory. The suspension pieces I built use QA1 3/4" rod ends w/ 3/4" to
1/2" bushings. The other end of control arm connects to a custom bracket w/
1/2" holes.
The holes shown in the picture are metric, just a shade smaller then 1/2" . I could just use the metric bolts/holes but it is a little sloppy inside the
1/2" bushing. It bugs me to go to all this work to "tighten up" rear suspension with quality rod ends, only to induce slop with undersized bolt. Thus my concern with trying not to hog out the hole too much... possibly inducing the slop I just removed by using the correct dia. fastener.
The metal is not too thick. I think I may try the cut 1/2" file or reamer trick. I'm afraid using a drill bit in this application may just tear up the hole given they are so close in size. I'll have to pick up a 1/2" file and give it a try with some vice grips. I'll try to grind a chamfer on the end to help align it with the hole a little better.
Thanks again.
Wayne