Reply To: 303977 cylinder head evinrude 25hp

[Don]

OK, well going by just the color of the Johnson head, it is from a 56-58/30 or 35hp. Like Frank says, those numbers you see on the heads are just engineering “casting numbers” that we have no way of “looking up”.
I don’t have access to 55/56 parts books…But, am wondering if the cylinder bore size changed between the 25 and 30hp models. If so, the heads will most likely NOT interchange, even though the bolt pattern is the same.
Why is it that you want to replace the cylinder head on the blue Evinrude??