That right there is half the battle! I restored a 318 '74 Charger twelve years ago and sold it to a guy that put a 440 in it. I recently bought it back from him and I'm doing a few things to it to give it a more original appearance. He DID change the crossmember for BB application, but didn't do anything with the passenger side fender. I now have to remove the motor to properly cut out the inner fender and add that large mat. I'm so not looking forward to that...