Performer RPM/383 question

First off, thank you for all of the responses to my initial questions about my new Dart/383 I recently bought.
My question is this. Currently there is a Holley Strip Dominator and Demon 650 Vac secondary carb on motor. I really think I want to change that to a Holley 750 DP and Edelbrock Performer RPM manifold since this will not see much, if any track time. The heads have been milled 0.060. If I get the RPM, how much will need to be milled off the intake to fit correctly? I appreciate everyones responses in advance!! Thank you!! (Yes, I am a chevy guy that has turned to "THE DARK SIDE"):finga: