Peice of piss mate
My notes on this conversion are floating about somewhere, they are very gay basic notes, I'll get it written up on my website sometime I think
You'll need these for the Crank Position Sensor & Signal.

As your S2 block wont have the provision for a CPS sensor, so you'll need the Sierra 1800 CVH alt pulley, CPS, bracket for CPS, alternator bracket and alternator pulley.