Frustrated engine wants to die at idle

Yes it does have power valves in it. One other point of interest is... i dont have any vacuum ports. I think I am going to have to drill and tap the intake (how large of hole?) or maybe I can use a spacer. I do have a nitrous plate on but not hooked up yet. So could I go: manifold, nitrous plate, spacer plate with vacuum port then carb? Would that work? Probably look dumb but workable? I still have not had time to deal with the distributor but I will do that soon. I understand the process thanks to all your help here and really appreciate it! Thank you.