'76 spider, installing a 4-2-1 manifold and downpipe. Any front or rear exh sections fit '76 to 80 - all the same? (no cat) Can I run straight back to rear muffler or do I have to instlall a front resonator also. Anyone installed a Flowmaster rear muffler, and if so, any part # recomendations? thanks to all and have fun!