The 351 wont bolt and go on that truck with a 5.4L. Lot more work then its worth. Harness, mounts, etc all different.

Now when you said a dead hole, no compression, or constant misfire on that cylinder? You'll find that doing a shortblock on that engine is pricey, as its more involved then say a 351, or 305 chevy. Might want to find a complete engine for it. May check LKQ. I've torn those engines down, and while it wasnt hard, it does require some tooling, and not to mention the work to get that engine out.