I HAVE A 1995 MERCURY 200 XRI AND I BROKE THE LOWER UNIT,I HAVE A BUDDY THAT HAS A 1989 MERCURY 200 LOWER UNIT THAT LOOKS LIKE IT WOULD BOLT RIGHT UP.WILL THIS WORK,AND WHAT IS THE REASON FOR PLUGGING THE TOP THREE HOLES ON THE WATER INTAKE OF THE LOWER UNIT.
