Ok so it's been decades since I had to tune a carburetor or distributor. I've been working on a 64 falcon club wagon (read as Econoline) that sat for a long time and now I'm trying to get it running. I've replaced the fuel pump, replaced points with pertronix solid state ignition, and rebuilt the carb (Holley 1940 w load o matic). My symptoms are running very very lean (must have choke partially closed to idle, idle mixture screw backed almost all the way out of the threads) and fast idle. My first thought is vacuum leak, but almost all the lines coming out of it are steel tube, except for 1" of rubber lines just to connect two ends (see pic). Am I on the right track thinking vacuum leak? Any advice on how to find it? Oh one other detail. When I pulled the carb appart the old gasket had scorch marks and the accelerator pump was melted. All replaced, nothing seems to have any fire damage, but thought I should share. Final question, I know what the line going to the distributor does, but what does the line going to the top of the bore (with the rubber bit) do?