The 67 GTX tips are angled towards the outside of the car the 68 go straight out the back like the road runner.look for the nuts welded in the frame to mount the brackets.if the car had duals with turn downs or single exhaust the hangers are different,my road runner came from the factory with turn downs but the mounting nuts for the chrome tips were there,just had to chase the threads and the mounting brackets bolted right in.hope this helps