Something like this would prolly work.
http://www.cpperformance.com/p-330-polished-43c-cable-seal.aspx

Ok, the diverter has been sanded/painted/rebuilt and assembled.

I have the cable here, and have mocked up where I want to put the handle.
 
I need to drill a hole thru the transom. (I have a split swim step.)

From what I've read, I'll drill on the drivers-side......to make the loop to where I'll mount the cable to the control arm.

1. Drill bit or hole saw?

2. Starting on the outside of the transom right?

3. Tape it to keep edges clean?

4. Hole just big enough to pass the cable thru?

Wait till you get the fitting, drill hole in the transom cover with a step bit a tad smaller than the threaded end and if the fitting is stainless it should thread the aluminum or see if you can set a spark plug tap to thread the aluminum for the fitting

That sounds good, I really did not want to drill the hull itself .

Thanks for the tips