Since I have an expedition that gets horrible gas mileage and 2 of my II's have 302's.
My 460 in my pickup gets 10-11 mpg. The 351W in the other truck gets 14-16mpg. Pretty good numbers really, and besides that they are paid for. I dunno what to tell you about the Expedition, other than it's a heavy pig and if it's a V10 it will certainly drink gas no matter what. As for the V8 IIs, if they still have the 2bbl on it, loose them. A small 4bbl is way more efficient than that 2bbl will ever be. (as long as you keep your foot out of it) Netting 17-18+ mpg out of a 302 is not uncommon, fuel injected or not.
Anyway I got questions, does the 2.8 in the II's have a front sump pan?
Not that I am aware of. However anything can be fabbed up, with a little imagination. The 2.8s were also installed in the Ranger/Bronco IIs and Aerostars that i know of. These are slightly different internally but should be the same externally. I'm not sure what the Aerostar pan looks like. The Ranger/ Bronco II is a rear or mid-sump pan depending on the year/application. A 4.0L or 2.9L pan may also fit the 2.8, but have no idea if this will gain you any points.
Does the 2.8 have the same bolt pattern as small block ford motors, or is bellhousing specific to that motor, or does it even align with the 2.3?
The 2.8L bellhousing is specific within its family. This includes the 2.6, 2.8, 2.9, and 4.0 engines. A 302 bell will NOT bolt up. Neither will the 2.3L I4, it's one of it's own aswell.
However a 3.8L V6 will bolt up to your V8 C4 trans. I have been running the 3.8L AOD behind a few V8s.
How much different are V6 motor mounts in the II?
Not really sure what you are asking here. The II 2.8L mount is specific to the II, Pinto, Bobcat, etc... but different by comparison with the Rangers, Aerostars and so on.
Do they require different frame mounts ie like changing from I4 to V8?
Yes, swapping between the I4 to the V8 or V-6 to V8, or I4 to V6, will need the corresponding frame stands and engine mounts. If going TO a V6 or an I4, you can source Pinto/Bobcat parts aswell to broaden your availability.
In your case, I'd look at a 3.8L swap since you'll be able to re-use your current transmission and probably alot of other things.
However, if you don't want to deal with the EFI, the carbed 2.8L can be stuffed in but will require frame stands, mounts, transmission, and any other brackets to run accessories that didn't come with the engine. And me personally wouldn't drive a V6 car unless it was a stick. So if you feel the same way, factor in pedal assy, cable assy, driveline, probably new clutch set and any little parts you didn't get with a donor.
**whew!**