+1 to what GTST said.
most of the skylines guys could tell you what is done to your car. i could prob do it, but you live down the coast and i dont.
but chances are they isnt alot done...if they are KYB shocks they could be adjustable but there would be a nob to turn on top of you strut tower.. check what colour your springs are too. that will tell you who makes them.
clutch may be heavy duty, engine will most likely be stock, you may have an upgraded fuel pump.
other then that...you could go to a cop shop i am sure they will tell you what is wrong with your car for free as well