A 19" pitch seems to be a lot of pitch for a 90. I had the same problem as you. I tried a four blade. It helped other issues. But the bow seemed a little light still. I got a set of transom wedges. That made a noticeable difference. I can keep the bow down and stern up in a bad head wind. Trim tabs would be the ideal solution. But they are mega bucks. Try a set of transom wedges. I got mine on ebay for $15 delivered.
I am currently running a 14" four blade. I lost some top end speed but my hole shot for an old 90 is pretty mean. I do have to pay attention to my revs when running low on weight. I am right at the max of my rpm range at 5500. I run a jack plate and wedges. I have no complaints. I will try and take some photos tomorrow.