Ok well im that friend hey sidd, lol... Ummm if you have a rb25det, you only need the exhaust cam gear and not the inlet, as people say the inlet didnt make a difference at all on the dyno..
The exhaust side is set @ -4deg which yields on average 10-15rwkw gain in the midrange... Definately noticeable when you put some stick into your car!!
In comparison on dyno figures to cars with the same set up - the exhust cam gear, mine still topped approx 10rwkw gain.
Its about a 2hr job with the right tools to pull off the old cam gear and replace with the adjustable one... It comes down to the tightness of the timing belt, as the cam gear cover has to come off, and you have to ease out the old cam gear.
Make sure you mark the lining up of your CAS before you take off the CAS and cam gear cover, so you know where to move it after the cam gear is on.
Take extra precaution on where the belt sits on the inlet gear, as you dont want it to move over a few teeth and wiggle the exhaust cam gear in after setting it @ -4deg...
Put it all back together, and I think you might have to move the CAS anti clockwise about 2mm to counter for the -4deg adjustment... Its either right or left?? But a proper timing gun would also help.