I have a 260 and can not seem to get the trim correct. I can't seem to get it to stop porpoising from 3200 - 3400 rpm. Less or more I can get it to ride fine. Any tips?

When the boat is out of the water I would take a yard stick or a 3 - 4 foot piece of wood and find the neutral points on the drives and trim tabs on the indicator panel. There was an article about this in Powerboat Mag a couple months ago. Basically, put the stick flat on the hull and ajust the drives/tabs until they are parallel to the stick. Then mark your indicators on the dash.

Once on plane and you have indicators in the nuetral spots then you can make small adjustments to reduce the porpoising.

Yep....What LM said..........
Running the tabs at neutral {level} helps alot of boats..

The boat will do that a bit, especially full of fuel.

Which trim tabs to you have. 12" Bennetts? 16" Bennetts? 280S K-Planes? I would highly recommend the last two I just mentioned.

Running them at neutral, or just below (tip even with bottom of hull) should help you out. If you have the 12s, you will have to drop them down a bit farther.

I have the 12's. Is it worth going to bigger tabs?

ABSOLUTELY! Best upgrade I have done to the boat. Do you have dual rams? The upgrade is VERY EASY if you do. Just remove the old tabs and plates, drill a few new holes for the new plate, (it has two rows of holes, and the lower row lines up with the existing holes, or at least it did on mine.)

Give Bennett a call, and talk to MJ Thomas.
http://www.bennetttrimtabs.com/help.htm

He could not be nicer; or easier to work with. Best customer service in the biz.