For those new at wrenching, you only need to know the exact clearence if it is off. To check the valve adjustment, just take the 2 feelers for the upper and lower limits and use them as a go/nogo guage. If the thin one fits easy and the fat one doesn't, your valve shims are just fine.

Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python