Reply To: 90hp vs 85hp Merury Force blocks/engines 1994

[Beno]

nevermind all,

after some painful research using parts manuals and manufacturers sites,  it’s evident that Mercury Marine changed this block design in about 1989
even though they maintained the base/bottom bolt configuration and gaskets. they did not maintain the side exhaust system bolt hole configs.. so although you can swap entire engines in similar configurations you cannot swap engines and change over the exhaust config.