popped the valve cover last night..
aside from a bit of carbon build up higher up (where there doesn't appear to be much oil flow) it's actually pretty surprising how little wear there actually is at 258k. Most of the head is really clean, and the timing chain components still look nice and tight (I was budgeting to replace it all, now I'm not sure it's necessary - maybe just a new chain, maybe not at all).
I had some fun playing around with the valvetronic mechanism. I was trying to see what the valve clearance is at TDC, but I think by default the intake cam is fully retarded so there's actually no lift at TDC, and I didn't have enough leverage to compress the valve. It might have to wait until I start disassembling things.
It was really tempting to just tear into it, but I need to make sure I keep things organized. All of the rockers are matched to each other and to the specific lobes on the eccentric shaft, you don't want to mix them up or the lift values will not be correct.
I'm going to have to find that youtube video of a guy in South Africa who takes apart and rebuilds his valvetronic head with his shoestring and a screwdriver, lol..