Cut fenders, install headers for P.steer???

I have a 1971 Ren II, I am putting on a power steering kit from Herm the overdrive guy (Herm and his kit! A+++). The kit puts the power steering box inside the frame behind the radiator so I can still use my pto winch on the front. My Question is that I need to remove the stock exhaust manifolds and put on some headers that will clear the frame on the outside. Are there any tricks to cutting the fenders/firewell for a clean fit? Any ideas which headers to buy? Anyone need 225 manifolds?? P.S. I am not exited about cutting my baby up!

 

For $135 I'd recommend the Hedman Headers from Summit. The new ball collectors are great. The price can't be beat either. As for cutting up the fenders/firewall bracing I'd wait to get the headers and then remove as little as possible.