I would rather not try to adjust pushrod valves with feeler guages. Over time the valve stem tip will wear a divot into the rocker arm surface and a feeler guage will give a false reading. Instead I turn the adjuster to snug so the pushrod will spin with some resistance then back off the adjuster a set amount and tighten. The A-motor screw threads are 1mm. so 1/4 turn would be .25mm., however the rocker ratio is greater than 1/1 (don't remember the actual ratio) so I back off 1/6 turn (one nut flat) or maybe less.
This is very much quicker and all the valves lash are very close to each other. There was a tool made for this at one time. It had a disk with numbers for various engine models.