Coolant passages are below the intake ports in some A-series Cylinder Heads. They can be large holes or small holes.
Overview
- Standard Datsun 1200 heads have no coolant holes on the intake side.
Interchange
A-series heads will interchange with either dry or wet Intake Manifold with the following caveats:
- If the intake doesn't have coolant passages, tap the head's coolant ports and install plugs
- If the intake does, but the head doesn't, cold-weather starting and cold-idle may suffer due to insufficient heat. However, warm-engine operation should be OK.