I changed to an electric AC # EP42S as recommended by Top End Performance where I purchased the carb kit when I went from a 32/36 to the 38DGES. I blocked off the pump hole in the head w/ a block off plate I made. Performance was better w/ the electric pump for sure. With regard to the run-on issue, it seems to plague our trucks w/ that carb. I have heard of good outcomes with the installation of an idle cut off solenoid in the carb. I have purchased one but have not installed it yet. Hope this helps.