We use the same measurements on the J as all the M_17s. We did move the plate back 1.25 inches in 1998 as well as the mast step. So the sail area is still the same, the J is identical. No performance loss. We've won the Cruiser challenge with this rig. And our 17 did a mid-winter crossing of the Pacific. It's not an issue and the stainless fitting is in fact Stronger with a better stainless backing plate. We lift the boat at Yacht Clubs using this Stainless tach plate. Being 1.25 inches back allows us to install a really strong stainless Backing plate over a reinforced deck area where otherwise access to this area would be Impossible after the boat is decked. The mast is back 1.25 inches as well. So the J is the same. We've never heard of an issue or a repair being done of any kind. Funny story. If you have a story about this come forward now. With photos and documentation. As opposed to actual true issues with older boats and people losing resale value because of Keel issues. Stuck centerboards and resale values plummeting. Our work over the years repairing and providing replacement boards is EPIC. I owe a lot to this predicament and have made enough money to buy 2 Massage Parlor's and a Bar in Bangkok Thailand. :-) Bob
