I have a 1971 Demon 340 I have had since 1979. In 2015, the restoration started. I am ready to order an exhaust system from Accurate Exhaust. They say they need the numbers off the exhaust manifolds in order to get me the correct pipes. The people working on the car can't find any numbers. Can anyone please tell me where I can locate the numbers on the manifolds? Or is it possible there may be no numbers to find? And also, if you purchased from Accurate Exhaust, are you satisfied with what you have? Thank you all in advance.