[3 Squids]

Welcome to the site!! You’ll find just about any info you need here with a little searching. As far as trim tabs I think the best bang for the buck are the Lenco Electric tabs. Very easy to install and a simple system. Wish I could help with the coolant issue but I don’t do IB/OB’s but general mechanical knowlegde makes it definitely seem you have a leak. If it’s not in the oil that’s a good sign. Still could be a possibility that the head gasket may be leaking either down the back or side of the motor you can’t see. Maybe very slowly into a cylinder?? Inspect any freeze plugs good. I’m not sure but I imagine there may be a couple inside the bellhousing that would be tricky to inspect. Good luck with her and look forward to future posts and pics.