I don't care what the instructions say, I always put a light coat of sealer (I use RTV) around the water ports on each side of the gaskets. I mean really, you want it to not leak the first time, right? A lot of times I agree with no sealer, because in some instances, the sealer will act as a lubricant and make the gasket "squirm" out from under what it's sealing, when you torque the part down. It's not possible for the intake gaskets to do that both by how they are made, and the fact they have bolts running through them to hold them in place. Which brings me to another point. You also need to coat the intake bolt threads with "some sort" of sealer (again, I use RTV), because the intake bolt holes go through to the under valve cover area of the head. With no sealer, oil will migrate up the bolt threads from crankcase pressure and puddle on the intake manifold next to the bolt heads and have you wondering where it's coming from. So seal the bolt threads, too. Just because the factory "didn't do it" doesn't mean it's a bad idea.