I finally started working on my mivec heads. I have an 09 engine. This has the single mivec solenoid where the distributor goes. The cross over tube goes to the back of the front head. I picked up another solenoid that mounts in the front head near the cam sprocket. The oil holes are not drilled. I thought I would just drill these and plug the oil holes on the back side. After looking at it, one of the holes is drilled at a slight angle. This looks like something I could mess up. I was wondering if anyone has drilled these holes? How deep did you drill? These heads are in really good condition and I would like to use them. I was also wondering if these heads can be swapped- put the rear head on the front. My heads are really clean low mile heads.