Scott, Here's my understanding of it. If I'm wrong, maybe somebody will correct me. In '67 they took the manufacturer's claimed dry weight of the car and allowed a 350lb reduction from that claimed weight, so with a stated F.I.A weight of 2,640lbs, I would gather that Chevy must have claimed a base Camaro dry weight of 2,990lbs. For 1968, the rules were changed to get away from arbitrary dry weights claimed by the various factories involved and established a flat dry weight of 2,800lbs for all over-2 liter Trans-Am cars. For '69, they bumped that weight up to 2,900lbs and I believe in 1970, they moved it up to 3,200lbs dry or 3,400lbs ready-to-race. I believe it stayed at that weight through the '72 season.