Just thinking off the top of my head here, but you'd have a much easier time going with a 4.6/5.4 swap, than you would a 351, unless you went carbed. Chances are the body harness and dash harness are the same across the board for the 3.8/4.6 cars, so you'd probably just need to source a K member, 4.6 + accessories, EEC, engine harness, fuel line, and pump, to get it running.