Right behind you on this one Wasa.
Please let me know how you get on as Ive been thinking of replacing my Pinto with a Zetec/ ST170 but would only be prepared to go for it if i could use the fuel injection system and ECU.
Getting hold of the right engine, modding the sump, moving the exhaust to the other side of the car - that all sounds quite enough bother and cost without having to tinker around and spend hundreds on bespoke manifolds, setting up bike carbs and rolling road sessions as at that point I'd be better off putting a Cosworth head on the Pinto.