The Fairmont 200 engines (1978-82 models) have the 250 head on the 200 engine (called a 3.3L engine, then). You may wish to mill the head, as the combustion chamber's volume is larger on the later head, which would lower the compression a lot if you just bolted it on.
The Granada series Fords had the 250 in many of them: the intake tract has a larger volume on these heads, in many cases. This does not seem to make a lot of difference in performance, unless you plan on doing the mod where you flatten the intake manifold and make it into a 2bbl carb, like a 2100. See CZLN6's "Falcon Performance Handbook" for details about this stuff: that book is worth every penny!
The "quick fix", low-cost upgrades I like are "junkyard upgrades", where you can add things like DuraSpark distributors, better 1bbl carbs (I like high MPG performance) and clutched cooling fans, to reduce hi-RPM drag (if you have a "flex fan" now, this will help).
If you have the engine apart, deck the block at least .030" so that the "head gasket bug" doesn't bite you, adjust the head volume for 9.2 or so compression ratio, and check with Mustang Geezer about cams and lifters.
If you only work on the head, look into the 1.6 ratio rocker arms (not cheap), smooth out intake tracts and raise the exhaust ports as far as your exhaust manifold will let you. Replace the old hydraulic lifters with the newer type that have a spring inside of them (and less leakage, for more lift). Get the famous "exhaust port divider" and weld it in, it's worth the effort.
Above all, have a ball! These engines are among the most forgiving I've ever had the good fortune to work with, still running good with even the grossest of errors applied!
