I also have a Phoenix Cruiser. The first thing I did was have the plant change out the battery tray for one that would accept the taller 6v batteries. My previous experience was that having the extra capacity to keep the coach heater going all night when boondocking would be worth the $400 expense.
Four years later I thought now was the time for the 6v batteries. I was stunned to discover that two Trojan 105 batteries (and all similar) have a larger base than two type 27 batteries. I cannot fit them into my battery tray... head clearance or not.
