So my 1974 Mustang II 5.0 has no exhaust and I am going to put a dual exhaust on with long tube headers with h pipe, 2.5in straight pipes and cherry bomb mufflers. I am going to have the exhaust stop at the rear tires so I don't have to go over the axle and have to move my gas tank. So my question is do I use all the same size stuff 2.5in that's were I am getting confused. Like my muffler inlet 2.5in and outlet 2.5in exhaust tube 2.5in header reducers 3in collector to 2.5in outlet. I am most likely going to weld a lot of this stuff on.