Not an expert, but I will say that I wish I had Jay's timing cover and adjustable timing gear a few years back when I decided to advance my cam in the truck.
Getting the timing cover off and putting it back cleanly required dropping the oil pan, and pulling the timing gear off. At least the Ford Racing timing gear allowed for multiple mounting positions. It would have been nice to open an inspection plate, loosen a couple of screws, move it and tighten it back up.
I'd have paid a couple of hundred bucks to avoid all the extra work.