Joe, the weight deal is pretty simple. Basically, once you exceed the max. weight for a class, you are bumped up to the next. You are allowed to weigh under the limit of any class but not over. If your truck weights 7700, you can not enter the 7500 class you need to go to the 8500 class - in whch case it would be to your benefit to add weight to get to the limit of 8500. If someone chooses to pull in a class where they are under weight, that is fine. It just works against you. Consider the weight designations as max. allowable weight for that given class.
Craig
Craig