[bigblockv6]

The mounting flanges on the exhaust pipe are the same that lead to the exhaust manifolds so it will all bolt right up. On my 68 I had a custom dual exhaust made up for it when I still had the 305E, when converting over to the 478M I used 351E exhaust manifolds and everything bolted right up with no modifications. The company the builds this particular exhaust probably was not aware of the availability of the 351E in 1966 considering only the 305 engine was offered from 1960-65.