A&P helping me do my condition inspection asks do you have the performance exhaust as it says on the checklist - "Performance Exhaust Bolts (AN3-35A) Replace at 100 Hours or Condition Inspection, whichever comes first."
If you would like to stop that you can get the center spacers from CC and insert and weld them to your brackets.i believe top bolt had close to 200 hrs the bottom one has worn almost thru @30hrs. Mine were always worn almost thru at 33 hrs oil change. I have had few people call me on this in the past so I did a quick sketch off my memory but you should get the idea. Just make sure spacers don't touch when the bolts are tightened.Pretty simple if you already have it off. They were still good when I sold it thinking they had 250hrs on them then.
Chuck