If you're out of the water, loosen the PSS and move it forward. Center the shaft in the tube with a shim block. If you lube the block and the cutlass bearing with liquid soap (Joy), you should be able to turn the shaft if it's true between the bearing and the tube. The shaft resists turning if it's out of alignment with the cutlass bearing. Once the shaft is aligned with those two, see where the prop shaft coupling is in relationship to the transmission flange. This should eliminate the shaft droop for alignment purposes. When the alignment is done and everything except the stuffing box is bolted up tight, with the shim block removed, see if you can still turn the shaft by hand.
My trawler has a 13' x 2.5" shaft supported by the cutlass bearing and the transmission. When I was done with the alignment, with a new 10" cutlass bearing, I could still turn the shaft with one hand.
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters