For the head bolts, you can get a 10-mm double or triple hex bit at most auto parts stores. The bit slips into a 1/2" socket so you can use your ratchet and torque wrench with it.

I was able to replace the cylinder head of my SDL without touching IP timing. I suppose it's worth checking just the same.

oldsouth, do you mean the A-B light tool or the timing lock tool?

Sixto
95 S420
87 300SDL