I just installed the 2.5" Summit kit and there were only 12 joints you could put clamps on and that is what they supplied. The reason for all the joints is so it could be shipped in a small enough box so as to avoid over size shipping charges, a good thing in my book.
I used two band clamps where the pipes go into the mufflers (easier to drop the front half if I need to remove the tranny) and two standard clamps to attach the system to the hangers at the back of the mufflers. I welded the rest together. I also put in the Summit X-pipe. The mufflers supplied with the kit are turbos. These are quieter and have a smoother tone at idle and cruise than the 50 series deltaflo Flowmasters I took off. I liked the Flowmasters sound and was prepared to put them back on but figured I would give the turbo's a try. I really enjoy the quieter ride at cruise and the turbos are staying put.