I was unfortunate enough to hit a BIG rock with the sceg and prop of my '87 Johnson 90 horse VRO outboard. I tore the sceg off and need a new lower unit. I found one on ebay off of a '75 Johnson/Evinrude 70 horse outboard that looks identical. My question is will the 70 horse lower unit work on my 90 horse VRO? Please respond ASAP for auction time is running out. Thank You!!