Dont know about the 4AC but a 4AGE is a bit of stuffing around, you have to undo the top engine mount and jack up the motor to get at it. It is about a 2-3 hour job if you are not 100% sure what you are doing.
Remember to use some loctite gaskets or similar if you do it yourself.
Are you From Richmond? I live out that way you may have seen me around....