Originally Posted by leathermang

Not exactly the secret handshake yet... and this stuff IS in the archives if you look good enough... where to find the wrenches, everything....

But the description for the secret handshake is that the valve is threaded on the top, either of the two nuts used to adjust the valve lash can be stuck so that the VALVE turns ( the retainer only turns because it has a cleat which goes into the mortise in the valve ) when you try to move those nuts. So if one or both of the nuts are really stuck then you can use the retainer to hold the VALVE with enough force to unstick either of the nuts which are tight.
You seem to be giving the impression that the screwdriver is an acceptable tool for this job and that those suggesting the third wrench are somehow spendthrifts or unable to use a screwdriver well... when in fact you have dealt with very few stuck nuts on these engines and it may be that the amount of abuse a stuck nut has had in the past may put the force necessary to move it in a different league from the ones you have experienced first hand.