I am finally getting ready to reinstall the engine in my 30-U after a complete rebuild and will be trying to use my Kingston vacuum tank instead of the electric fuel pump I used previously. Since the vacuum tank runs off the oil pump, as opposed to drawing vacuum from the manifold, I would think that some type of check valve needs to be placed in the vacuum line to keep gas from getting into the oil pump. Is there a check valve in the vacuum tank itself and if not has anyone added one in the line? If so, what did you use? Thanks.