The Autolite equiv plug is the Autolite 25. The motorcraft plug number is SP-450.
They are basically the same plug made by autolite. I've heard the motorcrafts tend to stay a little more consistent in resistance values but i have no proof of this.
I heard recently that the Autolite 25/Motorcraft relationship is long gone and the plugs aren't "the same" like they used to be, but either way they're both what i use. I'm actually going to be doing mine today and i'll probably go with Autolites 25s again, Walmart has them pretty cheap.
No change in gap due to change in timing.
The only reason to change the gap is if you are running something other than stock ignition (which is very good), pressurized induction or NO2. The stock gap is .052 to .056