Bulllitt man..
,
I went to the garage at midnight and checked for you. My two long hangars only had the two diagonal holes. They are either the originals, OR I replaced them witih GM parts around 1975 (too long ago, and I don't really remember but I did buy new muffler and pipes from GM at that time; the car hasn't been out of my garage since 1980, although I'm now in the process of disassembling and cleaning the parts for reassembly (which is why it's a bit easier to check these). My parts each have an 'Lo' on them (on the long metal strap portion), and a small '5' on the part that clamps to the pipe. One of them still had a piece of the paper PN on it. with the number 930087' (all I could read - it might should have a 3 in front of it?)..
the other two hangars actually had stamped GM part numbers on them. 3964858 and 3965633, with an M and 3 also stamped. Some of them had rubber which had 'white sections' in it (from the tires I suppose)..
Gary / 69Z28-RS