the pas system is the same on 1.8-2.0 8v and 16v engines, the only difference is the alternator setup. early ones have a massive spring under the alternator, later models have a seperate tensioner pulley. both setups can be swapped though if you also change the alternator bracket. waterpump pulley is also the same, but crank pulley is different due to the abf having a thicker timing belt sprocket.
the physical block is the same between 8v and 16v, though the 2e block doesn't have a hole for a crank sensor. the pistons and conrods differ 8v/16v, also so do the intermediate shaft, oil pump and timing belt sprockets. crankshaft has different part number, but i think its the same shape. something like abf is forged or something. not 100% sure?
BBM motorsport do an ABA->ABF conversion kit for the guys in the US, but I cant remember if a crank is included. I'd check but cant seem to get to their website
