My 72 Jimmy came with org. manafolds which look alright and dual pipes running back which are basicly shot. Im having a lot of exhaust fumes entering the truck, i belive they are comming through the tailgate since the pipe ends are right below the 1/2 inch gape below the gate. Is there supposed to be a seal there? Im putting a new exhaust system in next week and im trying to figure out where to run the tail pipes out. Im definatly going out the side, Any thoughts on comming out in front of the rear wheels? Any imfo greatly appreicated.