I never got my drivers license until 1973, so 71 and 72 was just a bit early for me. But in the mid 70s, I was running Fisk Sprint F60-14s (front) and G60-14 (rear) on my 1970 M code 351C 4V Mustang Sportsroof. It had the original Goodyear Polyglas F70-14 small letter tires when I bought it, which I still think were about the nicest looking tire ever made. But when the Polyglases wore out, the Fisks Sprints were about 1/2 the price of new Polyglas. A buddy had Mickey Thompson J 70-15s (with the "I" shaped treads), on his 4 speed 68 Chevelle SS 396, which at the time, seemed to hook up great. Other tires that I used in the mid 70s, were Road Huggers, and Concorde L60-15s, both worked decently, and Goodyear "Rally" GTs, which were great for laying down crazy long, and loud tire tracks, but virtually zero traction. Later on, I tried Formula 1 Super Stocks, Pos A Traction Torque Twisters, and Pro Tracs, all worked fairly decently.