Great idea Jerry. I will run that experiment. I can check MPG differences easily by just not using 5th gear. I will hook up a vacuum line to the manifold full time and record numbers at different RPMs and speeds. My engine is a good guinea pig because it freshly rebuilt and so is my Rochester B carb. This will be interesting. I was getting 18.5 MPG highway using the OD gear with my old worn out 250 engine and same carb.
