Some of you likely saw where we had some fun (that I instigated) after with Scott @ Harms blowing up a muffler on his test stand.
It was a tune-up issue on initial startup.

Well, Karma, I guess.

Yesterday I'm driving my K10, with the buddy I'd bought it from years ago, just cruising along about 30 MPH.
Truck's been running like a watch, not a hot rod by any means, just a nice restored truck I'd just driven about 35 miles, speeds 25-60.
Suddenly it starts popping loudly and intermittently out the tailpipes, kinda like shutting off, then clears up but it's a lot louder.
Drove it about 6 miles home where it ran perfectly, just...louder. (Obviously it had hatched at least 1 muffler.)
Exhaust is just basic 2.25", "Xcelerator" brand "turbo" mufflers, H-pipe, about a year old.
Blew right muffler apart, left is swollen up like a puffer fish.

I'm wondering what the heck caused that, when the thing's running fine. Even the tailpipes have that nice medium tan/grey color inside.