History: #4 *intake* valve kept tightening to the point that the engine
would be running on 3 cylinders. Since intake valves do not stretch
--unlike exhaust valves--, it was suggested that I replace the old valve
adjusting screws. Did so 202 miles ago.

Readjusted them yesterday and noticed that almost all gaps got wider by a
LOT (6 --i.e., 0.006"-- is the correct clearance for all valves on this
'75 type 4 engine): 

September 29, 1995: 140,325 miles
valves: 3E-1E   6-10
        3I-1I   8-11
        4I-2I   4-11
        4E-2E   8-11

I'll attribute that to the adjusting screws' "freshness" and hope that
more hammering will harden them. (Is that hope justified?) Note that #4
intake valve is still doing its own thing. Conceivably, the screw's
shortening was more than compensated for by the valve's stretching? Any
other explanations perhaps? 

-- 
Sami ('75 Westf.)
dakhlia@wuecona.wustl.edu
http://wuecon.wustl.edu/~samid/