I tried this on my 2520. My advice is don't do it. The longer chord planes were a waste of time and money on my boat. Take that money and get a good fiberglass man to plug the old holes in your transom. Then get some wider tabs and mount them up. You could use your old Lenco actuators with a wider set of planes or just get a big set of Bennetts. Here are the problems that I ran into.
Problem #1 - The longer tabs that Lenco sent me had the same hole pattern but I had to wallow out the holes in the hinge a little bit to get everything lined up right. The longer tabs were made with a much heavier and bigger hinge and the distance from the holes in the hinge to the running surface of the tab is not the same as the tabs that are on your boat now. This causes the next problem.
Problem #2 - Lenco tabs use a piano type hinge which will allow water to pass through. This is not a problem if the tabs are mounted 3/8" up from the bottom of the boat like Lenco states in their instructions. The 12 x 16 tabs when mounted to the original holes in your transom will be flush with the bottom of the boat. This causes a lot of saltwater to spray all over the motor where it is probably sucked in through the air intake. Being the master jury rigger that I am, I came up with a way to block the spray coming through the hinges. Then I discovered problem #3.
Problem #3 - The next time I put the boat in the water I was still getting quite a bit of spray on the motor so I handed the helm to my buddy and I went back to see what was happening. My rigging had stopped the flow of water from th hinges but now I could see water rolling over the side of the tab and the hitting the actuator where it mounts to the tab and then spraying all over the side of the motor. No good.
Problem #4 - Dale is right on with his advice. When I put the tabs down far enough to have the desired effect it really drug the boat down and the spray was terrible.
I wound up removing the Lencos and installing a set of 30" wide Bennetts and I am completely satisfied with them. I can now make the bow cut like it is capable of doing.