I went out into our warehouse to measure the Erickson Dock Cleat - Galvanized Steel - 6" Long # EM53400 for you. The holes are 1-1/2 inches on center.
There really isn't a trick to the system you mentioned, but this cleat will hold strong if you are willing to change from the 2 inch on center cleat. view full answer...
I went to our warehouse and measured Erickson Dock Cleat # EM53500 to get you the mounting hole spacing you need. Each hole measures 5/16-inch diameter and their centers are spaced apart by 1-5/8-inches. Please see the photo I prepared for you.
Thank you for asking this question since this important information was missing. I have requested it be added to our page to help other customers. Thanks again! view full answer...