I HAVE TWO OLDER 6X4 GATORS THAT BOTH NEED REBUILT AND I WAS WONDERING IF ANYONE HAS REMOVED THE ORIGINAL FD620 AND REPLACED IT WITH THE FH601. I THINK BUT NOT FOR SHORE IN 2005 JOHN DEERE CHANGED MOTORS AND PUT THE FH601 AIR COOLED ENGINE IN THE 6X4. PRIOR TO 2005 IT WAS THE FD620 WATER COOLED. BOTH ARE KAWASAKI. IF SOMEONE HAS, DID YOU HAVE TO CHANGE ANY OF THE WIRING OR REGULATORS. THANK DANNY