The intake valve cover has rubber gasket but still requires rtv in certain spots. The exhaust valve cover uses rtv instead of rubber gasket. If for any reason you are pulling the valve covers then you should also replace cam seals. On the front cam keepers there are 2 small veins/grooves in the cam keeper. You don't want to plug the veins with rtv, so only put the rtv in front of the veins. Also, like mentioned before the VTC also needs rtv on the intake valve covers. In the rear of the exhaust valve cover there are 2 half moon rubber seals. One on each side of motor. If you plan on pulling the exhaust valve cover I would replace those half moons as well. Most people goop those with rtv. I only put rtv on the top of the rubber half moon and a little down the side. Never had a problem. Same principle with the VTC. There is a rubber gasket that forms to the top of the VTC. I don't like using rtv where a rubber seal is. I only put rtv where a rubber seal meets the mating surfaces in the area where metal stops and rubber begins. Where the metal stops and rubber begins I put a tapering amount of RTV just like the rubber seal between the oil pan and the front/rear main seal like factory states. I also only use Permatex grey as per factory orders.
you have to know what you are doing. - 
