Shortly after I graduated from high school in 1963, I inherited my late grandfather's 1958 Chevy coupe. It was the bare-bones "Delray" model, nothing fancy at all, but I loved it. It had a 3.73:1 ratio rear axle and a 3 speed manual transmission, 14" wheels, and fairly low profile tires. I had no problem whatsoever keeping up with traffic at 65-70 MPH, and I saw the high 80's on the speedometer more often than an 18 year old kid really should have. It had a box stock 235 engine. Yes, it made some tortured noises, but it stayed together! I'm going to guess you can run 55 or so with the rig you've got with no modifications, IF you'll get the steering and brakes in top shape and keep the engine tuned well, and run some fairly tall tires.
Jerry
