sounds to be a fuel/vacuum issue. If you set the screws to max vacuum that should be enough fuel. Have you tried to turn the screws all the way in and stall the engine, both screws one at a time. That would eliminate anything plugged either side. Some of the early Holley Vacuum carbs had mix screws that metered air instead of fuel. So to make it rich the screw would have the be screwed in and screwed out for lean. The shroud I used is a Jegs brand for mopar to fit 69 B body 26" radiator. This shroud fit my 26" A body perfectly.