I need headers for my truck. the old exhaust is falling apart and replacing it with manifolds just isnt going to happen. i have an 85 350 and 4-speed trany no a/c and need to stay NY emmisions legal what would be the best setup/manufacturer. i know i want small tubes for the torque, but what size should i look for. also what about leaks. and do i have to convert to dual exhaust? thanks for your help.