Adapter plate help, stuck on project

[DamianJP]

Hello

I have a 1977 Evinrude 55HP powerhead.

I had to get a midsection which I found one from a 1975 Johnson 50HP.

Everything is matching up except the adapter plate, it has a small difference than my original off the 1977 Evinrude.
1977 Evinrude 55Hp adapter P/N is 321509
1975 Johnson 50HP adapter P/N is 315450

Both have a supersede chain that ends in 0351178. Take a look at part #56 for both motors..

1977 Evinrude 55HP
http://www.marineengine.com/parts/j...73D&manufacturer=Evinrude§ion=Exhaust+Housing


1975 Johnson 50HP
http://www.marineengine.com/parts/j...L75B&manufacturer=Johnson§ion=Exhaust+Housing


Can I make this work somehow with the 'new' 1975 Johnson 50Hp adapter plate? My older adapter plate from the 1977 Evinrude 55HP had a broken bolt which I drilled out and can be tapped with new threads but Im not good at doing that so Im tryin to see if this would work.

Heres the pics of the differences...

1977 Evinrude 55HP Hole in circle has no plug, just goes threw the plate.

1975 Johnson 50HP Hole is sealed with a rubber plug/seal of some sort.

Sorry for the long post , but I need help bad. This is driving me nuts.


Thanks,
DamianJP