I hate to be captain obvious here, but If you never turn your rotors they won't get out of spec. Unless you mess them up really bad by having a pad fall out or something. You'll get used to the hop if they get warped
I've had the same pair of rotors on a car for 9 years, just repack and re pad every year. Granted, it is not an everyday driver, but I assume an ol' 1970 Isn't going to be a daily driver either.