Fenderwell header holes in inner fender.

I'm looking into doing a modification to my dart and wanted to see exactly how much room I might have by cutting the passengers side inner fender where some of you guys do to use the fenderwell headers. (like how far forward into the shock tower area and how far back?) I have an early 63-66 dart and will need as much room in that area as I can get so pic's of the cuts without the motor in it anyone? I'd like to stay as far away from the A/C blower motor as possible,but will heat shield it if I can't get enough room.