Thanks all. Yesterday, while waiting for replies to my post, I decided my question might be silly and I might be over-cautious, so I went to AutoZone and bought muffler #24200. The shop manual says the exhaust pipe and muffler are welded together but can be cut apart to replace the muffler (and that if you ever replace the exhaust pipe, you'll also be buying a muffler....because they're welded together). I can't believe my muffler is original, so I'm guessing my dad (deceased Cadillac-Oldsmobile dealer and the previous owner of this truck) or his shop guy, has surely already severed the exhaust pipe from the muffler.
Anyway, I'm about to go down the path of replacing my own muffler, then probably buying a straight tail pipe from the muffler shop. After this is over, I'll add my opinion of whether it's easy, or I should'a taken it to a pro.
Same with the shocks.
