I am replacing a Evinrude lower unit with a Johnson lower unit. I notice there is a rectangular, kinda sunk in, looking box on each side towards the prop, that is not on the Evinrude. I am pretty sure it has something to do with the Exhaust. What are these and will it matter if I put it on an Evinrude?


Edited by BrazosRiverTom (07/07/17 08:28 PM)