I like the marvel. You may not need to rebuild it. Bolt it on and run it.you may have one in good shape. the fuel line is different for the marvel then the zenieth. The lenght of the carb is shorter so the stock line wont line up. To try different carbs i made a fuel line by cutting the middle section out of an old line and added rubber fuel line . This lets me swap carbs out to test different ones. And not worry about if the lines match up to the carbs.