The 1990 models had Indmar motors in most & had either the blower mounted to the rear of the engine or alongside the engine on a steel bracket. The bottom line is the suction hose is suppose to originate from the lower 1/3 of the motor compartment and then discharge through a glassed in 3" PVC tube alongside the exhaust toward the transom, then elbow up & change back to 3" hose over to the rear vent.