360 LA installing Promaxx Aluminum heads

As stated, the lifter should have .030- +or- .010. So the minimum amount of preload is .020 with the lifter on the base circle, pushrod in the proper spot in the lifter resting on the camshaft with the rockers bolted down and the adjuster at approximately of a half turn out from its seated position.

If your measuring for pushrods, put your adjustable pushrod length checker in as described at zero lash, in the proper lifter area, the rockers adjuster cup at a 1/2 turn from the bottom and zero vertical play of the pushrod should be adjusted in.
From there you can add a minimum of .020, .030 preferably as stated as the suggested preload lifter amount, .040 is now the plus .010 described above to the mean measurement and maximum.

In the second picture, the depressed plunger in the lifter is stated at .020 min, .080 maximum, ether the shaft on the non adjustable rockers needs to be moved or in the case of adjustable rockers, the adjustment screws needs adjusting in or out.

It’s been long said that it should really not be more than 2-1/2 turns out from the west for the adjuster. It starts becoming more and more of a breakage risk the farther it is from the seat. If indeed you need more than the 3 turns of the adjuster, you really need new pushrods.

Lightly loading the pushrod, .010 or less preload will start the lifter acting like a variable lifter.
NOT a recommend route to take.
To long of a lifter has the Hyd. acting closer to a solid lifter. NOT a recommend route to take.
Pushrods to long are worse than to short (IMO) but to long of a pushrod can lead to bad max lift geometry. It becomes exaggerated with greater and greater lifts.

I hope this helps.