Napa are good batteries but consider this...
The GC-2 Six Volt Golf car battery is a True DEEP CYCLE battery, this means it can safely be taken to 50 percent state of charge before serious damage to the battery starts happening.
And even if they are taken lower for a short period of time, they may recover.
Most 12 volt (The GC-12 is an exception, but then it is a Golf Car Battery (GC)) are starting batteries,, or MARINE/deep cycle, These are damaged way more by likely to be damaged, fatally, by a deep discharge, and the cut off is also higher.
I would replace with a pair of GC-2 or if that wont fit a GC-12, Costco, Sam's. or your local Battery Dealer. Mine are DEKA
Home is where I park it!