Engine Compatibility ...

anything built on a 1200-1600 block will fit - right up to "2.lots"

Type 4 motors will fit with the rare as hen's teeth 200 mm type 4 flywheel. Or you can hack some of the sell housing out and use a not so rare 210mm type 4 flywheel.

as said any 1200 - 1600 will fit, the problem will be with the clutch and flywheels, as they were different on early and late models. you need to check compatibilty with the gearbox you have.