My 5.8 has a bolt through the top of the beam and beam strap about where that stud is. I highly recommend you contact the closest Nacra dealer to you and get the original specs of the beam. Don't be shy about contacting them even though you don't want a beam from them now they know that if they look after you properly now you will buy something from them one day. Sometimes the beam isn't the widest part of the boat when you are beaming up a boat to it's maximum width you need to find the widest part on the sides of the boat and measure from there. You may not have a standard tramp so will need to be conscious of installing the tramp you have the way it is installed now or you will be up for money to modify the tramp. An original Nacra 5.8 front beam will have a track built into it to slide the tramp into don't know about your boat