I'm trying to find an answer to the original question as well.
I have a 98 GTV with a blown 1970cc CF1 twin spark, engine code AR16201. Finding a replacement CF1 engine for me is near impossible, but plenty of 147 and 156 1970cc twin sparks around to use if they are suitable????.
I assume that the 156 and 147 engines are CF2 and CF3's. The short motor, being a fiat sourced block with two balance shafts, seems to be the same for all three engines.
variations seem to occur between the CF1, 2 and 3 engines in; the 16V head, both camshafts, and the inlet and exhaust manifolds. Different ECU units seem to be used to match the variations.
Can anyone definitely confirm that my findings are correct or let me know what the real story is?
I would really appreciate some help and clarification.