Bennett Trim tabs, with "tracking" fins

I pulled the "new" boat out last week to change out the zincs, etc. Its a 22' cabin cruiser "Glasply", a deep vee, heavy little boat with a small block v8 and a mercury Alpha outdrive. The housing is vintage '78 the leg is new, it doesn't have trim detents, but if you hold both up/out buttons, you can bump it up a little.

I took a good look at my trim tabs, because I get a pretty nerve-racking corkscrew and yaw issue with minor adjustments. The trim tabs are a little oversized for the boat, I believe, and I thought that might be related to the erratic yaw and slight high-siding on the inside of a turn.

I found the tabs have two fins apiece, about 8.5 inches long and about 1&3/4 deep. One was pretty bent. I removed it and its matching fin from the other tab. The fins don't seem in line with the strakes (out by about 7-9 degrees) and I think I want to pull the remaining two fins off as well. I like trim tabs on a boat to level the ride port to starboard and to drop the bow down a little in the chop, but I don't like the steering effect these are having.

Am I on the right track here or should I just consider taking some height off the fins first?

 

Tough question. One sure fire way to find out though...

-Tom