Just browsing and i ran across this thread. Here's the parts-monkey chime in...
Fram HP-1 is the same size as the FL1-A a lot of us are used to buying. It's their 'race' filter. Much better than the extraguard POS that most people buy, but still a Fram.
You can use either one, if you are anal, use two, if you have lower oil pressure and/or are just looking to relocate it, use one.
The motorcraft I believe actually is a purolator filter, it's the high end filter and the middle quality case. I'd just as soon use the regular FL-1A if I were you or step up to either the Mobil 1 or K&N. You could also either order or go to the dealer and buy the Motorcraft race filter.
And just to flex the parts-monkey muscle... if anyone is just looking at this for clearance issues, the FL-300s will also work and is 1/2 as tall as the FL-1A.
The Swede