How interchangeable are parts between engine codes?

I've been offered a 1.4 which is an AEX, my engine code is ABD. The guy is quite sure i can just use the bare block and head, then just move over my existing inlet manifold, injector, dissy etc. Is this right?

It sounds worth it if it is compatible, because mines actually dying, he wants £60 and it's had new pistons, head gasket and bottem end rebuilt. Also means I can use it for experience if i ever want to do a conversion in the future

cheers