7 blade fan question

I own a 1968 Dart GTS with a 440 engine and have the following concern. First question is it acceptable to run a seven blade mechanical fan without a fan clutch? I have no cooling problems but the drivetrain has a vibration under acceleration. Second question what is the recommended fan clutch I should be running on this non numbers matching 1968 big block? The car was originally equipped with a 383 H code engine. Thanks for any help!