Bump the base timing to 16 deg. which will then increase your vacuum reading quite a bit. Then set idle speed to 850rpm then fine tune the carbs idle mixture screws for best vacuum.(you may have to re adj. idle speed a bit) After you are happy with the vacuum reading you can lightly tap the primary accelerator pump arm to squirt a little of fuel into the primary bore,if there is no change in rpm your set, if rpm raises your a bit lean if the rpm drops your a bit rich.