I am hoping someone might be able to help me. I purchased my first boat which has a 1967 Johson 1967 motor. I have been trying to find out whether you can use rabbit ear flushers on these models after being in salt water. I purchased the round type but it does not fit the motor as the intake slot is to close to the cavitation plate. I just purchased a rectangular flushing device, will this suit? and do I have to cover up any more intake holes as I dont want to use a drum every time I need to flush it.