What are the exact differences between say D16Z6 rods and D15 rods? I thought they were the same rods for the 1.5L VTEC's and the 1.6L VTEC's. I just put a JDM D15B in my cousins DX and I was curious if the GREDDY SOHC VTEC kit would work on that motor. It says in the Haynes manual that the block internals are the same. Hmmm... curious. and the tap for my oil line was easy. I just took it to a machine shop and they did it in a day and I picked it up after work.