



They really do have quite extensive cooling around the IN ports, if only the EXH/IN ports were seperated like these:
(This photo also shows the area behind where the 'triangle' shaped water jacket in the block meets the head, they can be drilled here and allow coolant flow directly into the head)


Really not much cooling down the bottom end of these heads at all, water jackets don't extend past the siamese exhaust merge:

This one shows the bulge where the 'D' section meets the 'O' section:
