I bought a sytstem from Ecklers, they have a few options, ours were the galvinized ones. If your using stock manifolds 2- 1/2, you must tell them what year, and if they are the type that dump down in the middle of the stock manifold (62 early) 409, or the back of manifold (late 62) , it makes a difference in the bend. Also if you use 2- 1/2 from the stock manifold to the muffler, make sure you order the right muffler size for the incoming and outgoing side of the muffler. That is if , 2- 1/2 in is good from manifold to inlet, then you have to decide what size you want the outlet of the muffler to be, it could be 2 ", 3" 2 - 1/2" whatever, but then you must buy the right size pipes that run to the rear. They will be made to fit over what ever size the outlet you've pick out. We have our body off the frame, so its been fairly easy, the bends are great and with a little help they fit great. I did buy the frame brackets, rather expensive, 180.00 or so. Here again you have to make sure you order the right size bracket kit for each end of the muffler and for the pipes going to the back. From Ecklers they use the exhaust system made in CANADA,
very nice, and they ship directly from the manufacturer. Ask all the questions before buying, this is one item I would call whomever, and talk and ask question before buying.