My 92 d250 is in need of another muffler and tailpipe (3rd each), and I decided to take the long-anticipated plunge and go stainless this time. What can I say, "I love my truck", and with only 174k, a stainless single stack seems like a good investment. I found the mandrel bends and pipe (going with 3") at auto-jet, and they seemed to have lots of pieces/parts for the do-it-yourselfer, including turbo outlet fittings and bellows joints.
I don't know if it's the New England winters or the way the trucks are driven but some diesels apparently do much better than others on exhaust systems.
There IS a world of difference between the various stainless alloys; 400-series (ferritic) stainless is not satisfactory for this application. Austenitic stainless (304) will hold up forever. The cost of my system is about half the price of the magnaflow. If you're handy with a TIG welder (or have a friend who is), this could be a rewarding project, literally.
Been a member for a while, don't say much, but read a lot. You have a wealth of information in these forums which has saved me a bundle, and been the source of LOTS of amusement

. Just thought I could give back a little.