When I installed my adjustable rocker arms (Comp Pro Magnums), I set the valve lash and then tightened the adjuster nuts. I just did the engine break-in and took the valve covers off to take a look and make sure everything looked good. While I had the valve covers off, I thought I'd recheck the torque on all the head bolts, rocker shaft bolts and adjuster nuts. The head bolts and shaft bolts were fine. When checking the adjuster nuts I found a couple that weren't as tight as the rest. I looked up online to see what the nuts should be torqued to but it seems there are varying opinions on this number. I found anywhere from 18 ft/lbs to 30+. So I set them at 25. The nuts that were tight still clicked the torque wrench at 25 but the ones that weren't quite as tight I had to re-tightened with my torque wrench till they were at 25. As an afterthought, I started wondering if tightening them further may have turned the adjuster in further and changed the valve lash. Being the nuts were tight, just not quite at 25 ft/lbs, do you think my tightening the nuts a little more may have moved the adjuster at all? When torquing them I may have turned the adjuster nut at most another quarter of a turn.

I had a jam nut loosen on a new motor, and the adjuster backed out enough to allow the pushrod to drop off the adjuster cup. I was over an hour and a half from home, got a DNF at a race I was involved in and had to get towed home.

Since then I always torque, loosen and re-torque the jam nuts at least 5 times or until the jam nut stops advancing more on re-torque, especially on new rocker arms. Most of the jam nuts seem to invariably turn 1/8th to a 1/4 of a turn more than the first time I torque them as they seat onto the rocker arm body further.

The mini torque wrench from LSM Racing is a great tool for running valve lash.

https://lsmproducts.com/products/tq-100-3

Not cheap (nothing from LSM is), but a nice tool

This one says "Preset from the factory to 22 ft/lbs, but can be customized from 13 to 28 ft/lbs.", but I don't recall mine being 'adjustable'... maybe an earlier model that was pre-set to non-adjustable 22 ft-lbs

Mine is about 3 or 4 years old and is adjustable.

I think you could take the head apart on a 3/8 torque wrench, drill the center for the allen key and reassemble. For much less $$

Always double-check lash after you think you're done.
Yes, it's possible that cranking the locknut by itself can tighten lash.

Sometimes adjusters will turn, sometimes they don't, when torquing. Best to double check those clearances.

One of these would be your friend. Think you will love it.

I use 17 ft. lbs. on 5/16x24 adjusters and 23 ft. lbs. on 7/16x20 size adjusters. I convert the ft. lbs. to inch lbs. and use a good inch lb. torque wrench to tighten the lock nuts.17x12=204 round up or down to 205 or 200, 23x12=276 inch lbs. round off to 275 inch lbs.
IHTHs

Have had one for at least 25 years now. Won’t adjust rockers with out it.

I like how the tool makes the job easier and is a torque wrench as well. I have several LSM tools and they are all great quality tools.