Thanks for the great info and pics, Mud E1. You're right, it does look like there's plenty of room to get to the spark plugs. I wonder if they'll fit an 86, even though it says they're for 90-95 F150's. I'll call the Ford folks at that number you posted - thanks!
As for the gaskets, I have no idea as to which side they're supposed to go on. I've installed a header before on a Toyota engine, but I've never done one on a Ford engine, and I've never had to use any kind of sealant - just the factory gaskets. I would think the side with the lettering should face out, just like you thought, but I don't know. There was a thread around here discussing how well the Ford Motorsport gaskets worked, but the discussion centered more on oil pan and valve cover gaskets, if I remember correctly. If there's a Ford Motorsport exhaust manifold gasket, maybe that would work well without leaks or the use of any kind of sealant. I've also heard that some sealants are not "sensor safe" and may affect the O2 sensor, but I don't know if that applies to Ford O2 sensors, assuming what I heard is in fact true. If it is true, then you might want to use a "sensor-safe" sealant if you think you need one, but my uneducated guesstimate is that a good quality gasket should be all that's needed. Maybe someone with more experience will chime in on that.
'93 302/E40D - The BroncoRican Beast