My father used 3/4 tons in his business that came with 4.56 rears. He installed 7.50x17 tires which are about 33" diameter. They all had sm420's. My favorite setup was a 270 with a 302 intake with a Stromberg WW. I had a 302 with a 3-1 setup, but it required constant tinkering. There were years in the late 50's when Texas issued driver's license to 14 year old kids. I got a commercial license to drive an 18 wheeler on my 16th birthday in 1959. Just because 228's had advertised hp at 3200 and 248's at 3400 doesn't mean they wouldn't go faster. Running them over 4000 was no big deal. Nothing ever happened to the bottom end. The trick was to keep the water below 200 and have strong enough valve springs to keep the valves from hanging open. That's why GMC's were popular with the serious dragsters and some 270's even ran at Indy. Driving like that was very unsafe. Brakes wee almost useless at 80. A puff of wind from the side could blow you over to the wrong side of the road. And we disregarded engine and wind noise. In those days I only spoke English when I had to which was in School. We had a saying that translates to "just don't drive any faster than your guardian angel can fly".
