Ok here is what i got. i just bought a 2000 donzi 33 zx and it has a pump out port-a-potty. I was looking to change it over to a toilet with a bigger holding tank. looking for advice on where and how to do the tank.

I know the tank is right side rear before the engine firewall...if you pull the screws out of the floor behind the drivers seat you can see the tank and pump...Since we are on the subject does anyone know if there is more than 1 vent for the holding tank?