as far as hp, i geuss its not really known yet as these engines havnt been played around with much, but having stronger rods/pistons/oil squirters,lower comp ratio and possibly a larger or stronger crank(wont really know till i get one apart) they should be good for 500-600hp but again i will only know when ive done it.
as far as bellhousing, i used the rwd auto housing that came with my engine, as the rwd one has the relief for the starter, where the fwd one uses a different starter location.