The 220 5.4 & the supercharged modular are about as similar as a late 70's 2bbl 302w & a 650hp V8 supercar engine. Same basic design only.

As for emmisions, what you would save on testing, you would pay a few times over on custom parts fitting any of the modular blocks. Worth the expense & hassle if you use a Cobra or Ford GT supercharged engine, but such a waste if it is the 3V 220.

Ive already measured up the bay...a modular will fit easily. So you wouldn't save anything on custom parts. So even a 5.4 3V will be less expensive development wise than a big inch windsor or cleveland.

Pete.

What about the crossmember & engine mounts, extractors/exhaust, wiring loom, gearbox crossmember, tailshaft, brakes & suspension to safely manage the enoumous extra weight..... Whereas a 351/5.8L Windsor block will bolt in (& plug in) with almost all the 5.0L hardware that is available at second hand prices. (EFI manifold & a few other 5.8L bits required on the engine).

I never said the modular can't be done. I just said the expense & effort would be wasted on a 220 (even a 290).

Yes engine mounts would need to be made but the stock crossmember will work. Extractors, unless you use off the shelf items for a very mild 351 you'll be in the same boat as the Mod engine. Just looking at the engine bay shape and steering shaft layout it seems BA headers will fit or fit with minimal mods. Gearbox crossmember is a non-issue...you'll need a stronger gearbox in either case. Brakes and suspension is a non-issue...the 351W or Cleveland is similar in weight to a 5.4 Modular engine and heavier than a 4.6 anyway and because the Mod engine is shorter you end up with more weight further back.
If you use an EECV from a stang you're in much the same boat as the pushrod V8 in terms of harness besides this is a 4.0L ute with a different harness(60 pin EECV) anyway.
I never said you said it couldn't be done but I think you underestimate the cost of achieving emissions legality and overestimate the differences in hardware changes to make the engine fit. In the end I think it will actually be cheaper to have an emissions legal mod powered XH than a pushrod one.

Cheers,
Pete.