In the last couple of weeks my 76 340 Plymouth Duster has been severely lacking in power once I get to 3rd gear. I guess there is something preventing enough gas into the carburetor, but I am not sure what it is. Everything is brand new from the fuel tank all the way to the carb, but the carb isn’t new. When spraying brake fluid around the carb while the engine was running, I noticed air is escaping from somewhere around the carb. Could changing the carb gasket be the problem or do you guys have any other suggestions? Also, the fuel vent line isn’t attached to anything at the moment. It is just open under the hood. I plan on getting a charcoal canister soon.