We could use aluminum bolts to retain our mufflers but their size would have to increase quite a bit to insure adequate strength. I think overall, aluminum bolts would introduce more problems than they could cure.

After a very bad experience with aluminum bolts that were retaining the carb on a 3W60 engine, I don't care for them anywhere on one of our engines. And yes, I know that DA uses those pretty red anodized bolts on many of their engines and even these get replaced on my engines. More free lance, back yard engineering on my part I guess.