Ive been reading a few posts and looking up how to measure Propshaft to Pad,When you Do this is the jack plate sappose to be all the way up or all the way down or does it not matter?

Ive got a 8'' jack plate on my ride with a 27p tempest plus 225 merc what would be the normal setting from the top to drop it down 3.0 3.5 ? or should I do my measurements and then decide I have noway of telling exactly where to sit it I was thinking of marking it or maybe a count....lol any ideas and am I on the right track here?

I think if I get this figured out it would help me allot on that chine walking.