I am beginning the same type of swap on a 68 fury 4door (why?) although I am not using the whole harness. I am going to splice the original harness with the underhood one from the Dakota. I have a friend with some experience in this, but he says there are only 5 or so wires to splice on OBD1. As for fuel system, I have a '71 tank in the car already so it has some vapor return ports. The LS1 corvettes use a fuel filter with a built in regulator, it has in, out and return, so I plan on using an inline pump. I was able to score a deal on a 95 dak with a 5.2 but a blown trans, but my car has a good 727 so I am going to use it for now. Sorry for the long post, but I thought I was the last one trying to do a EFI magnum swap!