I just replaced the two bumper fillers on the front of my 1986 Buick Regal. Naturally I had to remove
the front bumper to do this. I can't seem to find anywhere a specification for how tight to torque the
bolts for replacing the bumper to the support pipe. Can anyone help? Thanks.

Are you talking about the shock absorbers between the bumper and the frame?

It looks to me like this is just a straight pipe with a flange fitting on the end connecting the chassis to the bumper. I might be... could be...often am
wrong, though. Here'* a photo I snapped of the flange onto which the bumper mounts and I am just wondering how much torque I need to properly
affix those bolts.

A okay. I don't have an exact number, but good and tight would be fine.

If you want to do it by feel, see how tight the magenta bolts are when you loosen them, and make yours that tight:

Those get torqued to 55 ft lbs