Régis
I have a 32 and the ports are Beckson,I measured the outside flange and figured out the model by cross reference with a Beckson catalog online and just last week I replaced one in the head and it fit perfectly.The one problem I did have was ODay did not caulk or seal the core between the inside and outside fiberglass so I had a sloopy mess in between that I needed to dry out and fill with new wood and epoxy and I hope when I do the aft cabin ports this fall I don't run into the same problem.