Matty,
Your 272's would be 10.2 mm of lift so they would of had to relieve the head for the lobe to spin. As for the piston, im not 100% sure when that needs to be done. My last engne was running Tomei 270 @ 10.25 mm cams and the pistons were not relieved. Ask Chris (if he is doing the work) to pop a plug out and have a look.
Step 1,2 and Pro.
Step 1 moves 30 degrees and uses a 248 @ 8.6 mm cam. You can run that with stock pistons. Dan (Silver Nur) ran this kit on his engine.
Step 2 moves 50 degrees and uses a 264 @ 8.7 mm cam. You need to have pistons relieved for this kit. Step 1 and 2 are the same price.
Pro moves 50 degrees also and uses a 264 @ 10.0 mm cam. Like step 2 you need valve relieved pistons. This kit is expensive because it comes with an ECU which you pretty much chuck in the bin (You wouldnt use it). Unfortunately you can't buy the Pro kit without the ECU.
Here is Dan's result using the Baby step one on his 2.6/2530 setup.
Extra 50% torque (300 nm vs 450 nm) at 4000 RPM.
What setup did you use on your Nur? I can't remember now.
I chose step 2 because it was no more expensive than the step one but i'm going to try and use my current intake cam I have in the car at the moment. It cant be too hard, its just a bit of machining.