I have a Quick Fuel carb on my engine. I know it's a 4 barrel and I want to say a 850, but want to make sure. How do I know what carb is on it? Is there a number somewhere? The carb was put on years ago by my builder and don't know where the paperwork is. But my main question is; I need to change the power valve, I have the cover off but how to get the next segment off? Any help is appreciated!