1984 to 1971 Evinrude 50HP power head swap

I have a 1984 50HP Evinrude that had thrown a rod bolt through the crank case. Now just recently a friend of mine who has a 1971 50HP evinrude and had torn up the lower end on some rocks. Now my question is can I take his powerhead and use it with my lower unit? Any help would be greatly appreciated.

Re: 1984 to 1971 Evinrude 50HP power head swap

OK, now youre REALLY taxing the ol memory bank! Lol!<br /><br />Weve done newer p/h to old mid section. The main thing (I believe) is the the older block has a curve or indent in one side of the base for the shift wires from the lower unit. Your 84 should have a straight mounting base area. <br /><br />So -- if we put the 71 on your 84 mid section there will be an open area that exhaust fumes will come up thru. You will have to weld a piece in there to match the mounting area of the adapter plate.<br /><br />OMC used the same base gasket for both because they added a piece of material to the gasket. It made a small "O" looking deal. <br /><br />Also look at the area that the shift linkage (on the 84) bolts to. Compare that to the block of the 71 which will not have any mechanical shift linkage. I THINK you can put your linkage on the older block. Maybe not.<br /><br />Interesting project! Good luck!