You can use a bigger cam, but don't go crazy. Maybe ten more degrees than one recommended for a 440, if you are going over 500 inch. It is best if you get someone to spec out a good cam for what you want to do. Talk to Dwayne (fast68plymouth) who answered here. He can set you up with a cam that will match your needs and make plenty of power. Dwayne has lots of experience and dynos a lot of motors.