The mickeys don't need to be heated either.
I went from a regular 275/60/15 on the back of the 68 to a 275/60/15 et street radial and nearly shit myself. Never knew how fast the car really was until I put the mickeys on. Never once heated them but I could actually put the power down where anything over half throttle with regular tires in first or second gear was hazing the tires