I had a porposing problem too, then I added a ride plate and shoe. Sarted out at 0* on ride plate and now it sits at .75*-1* down, porpose all gone. The trim-a-steps were really down (5*+) when I got the boat, now they are at 0*. If they weren't already there, I wouldn't have put them on. This maybe speed dependent too. At how fast is the porpose?
Hope this helps
Daniel