Finally bit the bullet and did my exhaust manifolds at 187k miles. Well, paid an independent shop to do it because it's already almost 100 degrees here and honestly it looked like a pain. Paid $1,646 bucks, was supposed to be $1,350 but mechanic found 5 broken bolts/studs and 3 were broken off below flush, so had to pay a bit extra on labor. Glad I took it to the shop, I don't have a welder and the thought of trying to drill those 3 below flush bolts in awkward positions is not my idea of fun. I will pick up the truck tomorrow, looking forward to driving without the constant ticking from the exhaust!