Here is a reply from Colin Mack of Mack Sails in Stuart Florida. I asked hime to help us out on this. I recommend you call or email Colin.
Colin Mack
colin AT macksails DOT com
www.macksails.com
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Thanks for keeping us (Mack Sails) in mind, unfortunately it is not that simple. Depending on which brand of furler you have and how they were set up, the luff can vary by as much as a foot. The proper thing to do would be to buy a tape measure at Home Depot and run it up on the swivel like we instruct in our sail measurement video. Many of the boats came with harken or schaefer standard and there was a custom fitting made for some of the harken for us to get them up a little bit higher but not all. Fortunately however the spars were almost identical year after year, if we had a picture of the furlers and attack height measurement we can actually calculate out the luff dimension for this person or anybody for that matter. In the case of your boat (Hayden's IP 35) you have a harken unit one and unit two. We have those dimensions on file. I tried to jump on the form but I need a sign in as a guest which I did not have or could just be that my smart phone isn't that smart. Thank you again and please feel free to pass along my cell phone or email to anyone who has a technical question regarding any of our services. Hope you have a great day call me anytime
Thank you
Colin B. Mack
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