A permanet head was installed when I bought mine
There was already a permanent head installed in my 1985 25.5 when I bought her. The tank was installed underneath the vberth. I think it is a 12 gallon tank. There really is plenty of room down there for the tank. Although it does cut down on storage space. On mine there is a 3/4" seavalve on the port side next the tank underneath the vberth for water intake into the head. And there is a 1 1/2 (I think, it's whatever size is standard for sewage) seavalve on the starboard side underneath the vberth. The pump out fitting is just forward of the diesel fitting. And the values and manual pump (whale) are to port in the handing locker area adjacent to where the head goes. I don't think I have any pictures but I will look. Just a tip if you are going to do the installation, don't skimp on the hose. I would only use shields sanitation hose. For a year before I replaced them all, I had inferiors hoses from the previous owners install and it didn't smell pleasant. I think I ended up using 12 feet of hose. Good luck. Let me know if you need more details.
