From what I understand rule of thumb is put a level on the bottom of your boat. for every 12 inches bracket length you raise your motor 1 inch. example 24 inch bracket offset cavitation plate is 2 inches above the bottom of your hull
I just installed 12 x 12 Bennett trim tabs on my seafarer and they work well one thing I have been told if you leave your boat in the water use hydraulic if you have a boat on the trailer use electric
There out there I bought one 8 weeks ago, dry stacked most of its life, ( it’s a 1989 ) I replaced all the thruhulls didn’t find any water or rot in the transom, hopping I don’t have to replace the tank