I managed to tinker with the rear truck and get mine to a place where it can drag all ten cars around, even on the 2% grade.
I suspect you might be able to move the tach if you were so inclined, that might be an interesting exercise. You just extend the three wires and use a printed tach strip for the front motor. You'd probably have to bond the tach reader to the motor with spacers and CA adhesive instead of the bulky motor mount.