You can use the air grabber box with some slight mods for mounting to hood. Also the flap door and vacuum actuator are the same. The hood door will work on 71-72 Dodge but not on Plymouth. Switch, solenoid and vacuum can are different.

70 Road Runner 383-4 4 speed FJ5 & black guts
70 Charger R/T 440-4 4 speed FJ5 & white guts