We are going over alot of these topics right now in this thread. Is your truck a RC, EC, or CC? Around a 100 shot, your engine internals will be fine. However, there is always that chance your tranmission won't make it. Two runs a week won't be too hard on the motor. If you want to upgrade to a 150 shot, then you are going to be putting ALOT of stress on everything and something will break eventually. Don't plan on going down a spray size...I don't think I've ever seen anyone have enough will power to do that...haha!