Replacing two 6 volt house batteries with one 12 volt

[Monaramblee]

08 Holiday rambler Vacationer diesel
with two 6 volt batteries for the house and two 12 volt batteries for the chassis.
I would like to replace the two 6 volt batteries with one 12 volt marine/rv battery.
We dont dry camp anymore. Any issues with this idea?

[time2roll]

No issues but I recommend a G27 as a minimum. Are the GC2 about shot?

[CA_Traveler]

No