I was just about to bolt on a head when I noticed something strange- a
bit of the red sealant on the gasket was clearly visible from the rear
of the engine. I looked closer and saw that near the exact center of the
head, an aluminum cast ridge extends from the top down toward the base
of the head where it should mate with the block. The ridge begins just
below the intake ports for cylinders 2 & 3.  I have several other heads
here, and all of them have this same ridge, but it extends all the way
to the block, allowing a nice seal with the head gasket. However, the
head I've rebuilt and is ready for this engine has a ridge that stops
just above where it should mate with the block- Maybe 1 cm, or so.

Someone must have seen a head like this one. What's the story? Does it
require a special head gasket? Is this difference something to worry
about? It seems that I may not get a seal around the perimeter of the
head/block due to this feature.

I hope this makes sense to someone. I can provide a picture if necessary.

Waiting anxiously,
Brad Flubacher
State College, PA