I checked my valves about 5k miles ago. They were all approximately at minimum tolerances. I am now at about 41k miles and checked the valves again last night. All the intake valves were at 0.18mm (spec is 0.17mm to 0.23mm) and the exhaust valves were at 0.22mm (spec is 0.25mm to 0.31mm). I also noticed that the line at the "T" mark at TDC did not line up with the cam markings for the top of the head and had to be rotated about an 1/8" to line up the cam marks. Is my cam chain stretched or is this normal? Is there anything else I should check while I am in there like compression or leakdown test? Should all the valves be adjusted to the middle of the specs?