Anyo know a good way to remove the thru hull studs on a gimble housing? The ones I have are pretty corroded.
They feel like they will snap if I keep trying to turn them.

I would use a gimbal housing stud remover tool
sorry I couldnt resist that comment.

I am trying to do the same thing also, but not having much luck. Really don't feel like replacing another $1500 gimbal housing if I break off a stud. You could try a little heat around the studs, but it would probably lift the paint.

Ive soaked them for a week in PB Blaster , Havent tried the heat thing yet. I 'm not too concerned about the paint. Im just afraid of snapping it.

Mercruiser P/N?? In other words BIG pipe wrench!

Heat the aluminum casting around the stud,Aluminuim has a faster rate of thermal expansion than steel .

I use a stud removal tool that has three rollers in them to grasp the stud, heat the housing with a heat gun slowly.. bring up to temp. You can get it hot enough to hurt when u touch it.. with a heat gun and not hurt the paint. I would try bouncing on the wrench easy.. to see if it wil break loose. Is that stud SS or just steal?? I have done the above procedure with SS studs.
Hope that helps.. good luck!

Salt water huh?
Been there.
Propane torch. 2 nuts on the fine thread end. Put a wrench on it. Then a few whacks with a hammer. Have a beer and start over.
You know, the standard methods. Sorry, dont know any easy secret method.