I was on the dieselpuller.com site and was reading through the rules and had a question I was hoping someone would answer for me out of curiosity. It said that two 7/16" bolts needed to be placed in the exhaust at right angles to be legal to pull. I've never sled pulled and probably won't, (at least untill I can afford to break stuff) but don't know the first thing about it other than its a lot of fun to watch at the county fair. What is the purpose of these bolts and where exactly do they go in the exhaust? Could someone explain. Thanks