First thing's first; Hi everyone, this is my first post, awesome board you guys have here. Now that that's out of the way, onto the task at hand: A friend of mine has an old Peavy that he wants to turn into a 7 string. While I don't know much about it, I do know that it has a bolt on neck. My question is how he should go about making the neck cavity bigger if at all so as to accommodate the wider neck. This will also determine how he makes the pick up cavity bigger to match up match the string positions. If you need to know more, just ask and I'll probably be able to get the information from him. Thanks in advance!