I have an older (1999) Hardrock with the original rear derailleur. It's a Shimano MC-18 lower end RD that has performed fairly well all these years

I believe I have already figured out the answer to my question, but would appreciate other expert input. My question is this: when adjusting the high (7th gear) screw, what positioning of the upper/guide pulley should be used?

I assume on most (if not all) RDs, the upper pulley has room to slide from side to side. On my RD, this is ~1/16-3/32 in. (or ~1/16" either direction from center). Given that adjusting this pulley means to align it with the top (in my case, 7th) gear, where should this pulley be positioned when doing the alignment. I've placed the pulley as near-center as I can tell and the result has been OK. However, when I place the pulley to its far-outside position and then adjust, that seems to work best.

Have I got this right?

Here's what the Shimano RD adjustment guide says:

1. Top adjustment

Turn the top adjustment screw to adjust
so that the guide pulley is in line with
the outer line of the smallest sprocket
when looking from the rear.
After this, install the chain.

...but it doesn't mention where on the shaft the guide pulley should be placed


Thanks and cheers...Steph