On mine I have a flooring (basically) from the top of stringers to the side of boat making access to lower bolts very difficult, it would require cutting an access hole and re glassing so I decided not to go with K-Planes. I wonder how lagging the lowers where there is no access and thru-bolting the uppers, if accessible, would work.

Can you cover hole with 4" deck plate? Gives you inspection access in the future.

I don't understand, why fool with the Bennet tabs? I also don't understand why Formula put them on in the first place. They are a good product but IMO a high performance offshore boat is not the correct application.

I have recently seen some used Dana tabs and pumps advertised in the forums. Get them and be done with it, JMO.

Padraig

lenco upper ram mounts screw in like the bennets..

I have blown the upper mounts off the back of the boat before. I now run k planes.

For god sakes just buy some tabs and enjoy your boat....

I extended my bennetts on my 242. Worked great.

I went from ST-12 to ST-16 Bennet tabs on my 26' Sonic years ago. It was a noticeable difference.

But I also blew out one of the hose fittings inside the bilge on one of my ST-12s before the upgrade. This was on a bit of a rough landing on that side of the boat on a river run.

Your bigger tab is going to put more pressure on your hydraulics system.
The ST-16 comes with a mounting plate with two rows of screws, not just one row like the ST-12s.

Call Bennett directly before you do anything with a fabricator. They set the standard for Customer Service in this industry. They also chime in here on OSO from time to time.

Yeah, what does the boat do without tabs and the drives trimmed a notch or 2 out? Trim in to clear it up.
You do know that Formula sets the spacer in the trim pivot in a + trim out position....

Well, all good advice. I appreciate it.

I called Bennett and talked to one of the tech guys and he said that they sell a 16" tab that uses the same two cylinder design...so the hydraulics are good for the 4" longer tab. He then said that the 16 tabs could be purchased, but the location of the cylinders is a little different, so where they mount to the transom would have to move....he said it would be better to simply weld an extension on the ones I have. Lastly, he wanted to use the transom plate from the 16" tabs, which has double the number of screws, so there is no issues with them pulling out. My goal is not simple, but this will be a fairly quick upgrade. the idea of wiring for two pumps, all new hydraulics etc is a lot...

I am happy with this....as I was almost ready to pull the trigger for a set of Kplanes. While that may still be in the cards for the future, this modification will work.

Thanks for the advice. I will now resize the tabs, order the plates and get on with it.

With the extended tabs you will need indicators, Oh wait, I have a set of New Bennett indicators in the swap shop for $250. Good luck and keep us posted.