I have a Holley 2980 2 barrel carb on a international 345 engine in a dump truck. I'm having some trouble with it. I'm in the process of rebuilding it right now, and it was suggested on another forum that I should put a power valve check ball kit in it. The problem is I can't decide what hole I'm supposed to drill out, because this carb is way different than what the instructions are saying. So can anyone tell me how to identify the power valve passage where the check ball is supposed to be installed?