I used an older version of the scupper cart with the early tandems and had no problems, but the hole walls were much thicker. The cart arms were about 6.5" long. I believe these holes were made specifically for the cart. If you want to try it, double check the material thickness surrounding the holes (using a flashlight from the outside, look in and see if there is any light unusual bleed trough indicating a thin wall). Make sure your cart arms extend slightly less than 7" up so the boat is resting on the adjustable stops or tennis balls rather than suspended on the underside of the deck at the top of the holes.
Yes, the crank arm pins are upgradable to the current style. Tell your dealer to make sure you get the black ones rather than the newest gray version for a good fit. They should work great!
