I vote for the Marvel. I have a rebuilt (with flow tested jets) Zenith. My 29 tudor ran fine on it, but was subject to stalling when stopping since the float action is in line with the car's direction of travel, and is subject to inertia. Even Zenith must have realized that was a poor design since they changed it in 1932 for the model B. Rather that fiddle with the float level I decided to try (at the recommendation of a model A mechanic) a Marvel. My tudor loves it, and seems to have a little more "zip" than with the Zenith.
Am I worried that my tudor did not come with a Marvel in 1929? Since my tudor is running a 1936 diamond block engine, not really.
