I use gel super glue as a thread locker on metal to metal contact...works great....except on my OS 1.60....it eventually backs off...so I drilled a hole in each bolt head and safetied wired the bolts...If you don't know what safty wire is, it's genarally 20 or 32 thousands diameter stainless wire (can be 40 thousandths)...and you run the wire through the bolt head and twist it...route the wire so the bolt can not lossen..route the safety wire to the other bolt for the muffler and insert one leg of the wire into the hole you drilled in that bolt head so that that bolt can't lossen then twist the ends of the wire together cut off leaving a pig tail and fold over so you don't cut yourself ...now your bolts can not lossen...if I confused you I bet there is an explaination on the web on how to do it with pics...it's easy Good Luck