For the 1966 Model year there was only one Mopar Muscle Car motor we would be concerned with and that was the Hemi. Our 1966 Hemi exhaust system comes with the correct 2 1/2″ H – Pipe with correct flats for the torsion bar, correct welded on heat nipple, correct welded in cross over pipe, correct flanges our H – Pipe necks down to 2 1/ 4″ where it goes into the muffler because that is the way it was done. Our kit comes with the correct hemi style mufflers with correct flats, correct tail pipes with angle cut and weep hole, correct rounded bottom style mopar clamps, correct double loop muffler hangers, and tail pipe hanger, installation instructions diagrams and sealant. Ask about our concourse muffler hangers and show package for the guy who wants to compete on the show circuit.