Bill were you running another carb on this engine and just swapped to the new 750 and this condition appeared? Also does it run away with no throttle hooked up? If it is a vacuum leak I use propane to find them. Hope this all has not been addressed previously, am late to the party on this one. Nico Over Va. Beach, Va. 63 Dodge 330 64 Plymouth SF 65 Bel II vert ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! 1962 to 1965 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html and http://www.1962to1965mopar.ornocar.com/general_disclaimer.html.