thanks for your response, Im sorry to say the Roadmaster was a four door, it sat around my house for over 15 years before a move forced me to have it hauled off, only got a few parts off of it, the manifold and wonder bar radio among them. The carb I got from kanter is apparently the wrong carb for that manifold or it may require a special gasget or plate to work. How many rochesters were available for '56. I wonder if an intake manifold gasget is available that would block off those exhaust port. Thanks for the info on the counter weight too. I,m learning as I go.