which engine do you think would get better mileage, 1956 265, 1970 350, 1958 235? Mated to T-5 and 3.42 open rear in S-10 chassis (working on rat rod), have several motors laying around. I'd like to stay low on investment, so carbed, maybe elec ignition, but no aftermarket fuel injection or anything. Hoping for around 18-19mpg.