And judging from that information and floor plan it would look like you actually have three tanks. One 27g gray for the galley, one 27g gray for shower and bathroom sink and one 27g black tank. There will be a single dump outlet for the galley waste tank toward the rear of the trailer.
2016 RAM 1500 - 2016 Keystone Laredo 265SRK
The road goes on forever and the party never ends.