[Popeye31]

Mine will drive 55 all day long no over heating problems. a friend of mine was following me home one evening after a 65 mile trip and we had to jump on the interstate for a 3 mile stretch. when we got on I gave it a little more gas and my friend called me on his cell to tell me he was doing 62 MPH and that he had never gone that fast in his A and I was steady walking away from him the whole way on the interstate.no over heating. the Model A cooling system is a non pressurized system so theoretically you should be able to drive it with out a cap at all. I would say make sure at those speeds your timming handle is all the way down. also have the radiator checked out, cant heart to have it cleaned , make sure if some one has put a thermostat in that it is working properly, I dought the water pump is bad unless its the original one or it is leaking and you would know if it was leaking as soon as you start it up. I suspect you were driving with the timming lever not pulled down or timming is off or you have a leaking cooling system or it was low to begin with.