Keep them guessing. We built a 340 in the 80's in a 4 door 67 Dart. Used the 273 valve covers and air cleaner. Double gasketed the valve covers so the rockers wouldn't hit them. Used to go hunting Chebbies and Ferds. A lot of the hated that a 4 door 273 car smoked them light to light. Fun times. Even now my 422 looks just like a regular 340. Still have fun with it .
Second thought.:
Absolute overkill, waaaay overpowered, totally impractical... All you will do is spin the tires when grabbing the next gear. Especially at at 60 MPH. I just can't help to love it.