Bought a new 25' x 25" with strakes for a good deal and ready to install. I am bolting a 2 x 2 x 1/8 sq tube across the existing riser. They will be 36" long for easy access for bolting to the cross member. Think I will use a U bolt type. My floor allows me space above the crossmember to do so. This allow for the 3rd to be 3" lower in the water than the outside toons.