Hey Deffe,
I am working on my write up right now for the S14 motor into an s13 car, The wiring is pretty easy if you use the ECU pinout that silvia007 posted earlier on this page. There are two plugs that are by the fuse box in the s13 engine bay, The wires for these plugs need to be extended to under the dash where the s14 wiring plugs into the dash, not to the ecu. You can find the pinout for these plugs by the fuse box at
http://www.heavythrottle.com under the wiring section.hope this helps a little. I will try to get the wire colors and where they go soon.
Oh and SR BEAST, stock for stock the S14 motor will be faster than the S13 motor. S14 has bb t28 turbo, VTC, and other minor things.But its said that the S13 motor has a better head design with the High port manifold which flows better than the S14 low port manifold, So the best motor really depends if you are going to keep your motor stock or you are going to spend some money, However through my experience they are both somewhat similar.
-Jon
Modified by DriftBandit at 9:27 AM 10/9/2004