I have the same engine in an F150, same year too. One man's opinion only, but this is a job for a dealership that has done the repair many times. Your mechanic will be reinventing the wheel as he goes unless he has performed this specific repair before. Sounds like it will be pricey with almost all of it in labor. If the engine has to be pulled why not do both head gaskets while you are at it?
Best of luck to you. I hope you will keep us posted so we know how it all turned out.