Dennis,
way back in 56 a new plymouth 230 cu in was road tested by Tom McCall of popular mechanics magazine. He posted figures of 23 MPG at highway speed,....how they preped the car I don't know,......my 54 Dodge 230 is also a 3 speed, with Ford 2.75 gears and a few other better performance parts,.....shows 22 inches of vacuum at 50 MPH on flat highway,......and will never see 25+ MPG at 65 MPH,.....maybe there is a fish stuck in my carby.
Cheers
Bob.
