Anders, which direction does the arrow point (on the side of the PCV valve)? Did you push the hose over the threads on one side of the valve? Rockauto.com sells PCV valves that have push-on hose fittings on both sides. One example is the, STANDARD MOTOR PRODUCTS Part #V112. This valve goes on a 1978 Pontiac with a 350 cubic inch engine.
Marcelo, using the air cleaner is a 'passive' vent system that doesn't use a PCV valve. It is still another good way to reburn block gasses. They usually come off the valve cover with a cap that has a hose connection and it leads to the side or bottom of the air cleaner. I like the kind with the small filter on the inside of the air cleaner to trap oil and solids. Even though the passive system doesn't work as well, I really like it because it never messes with the fuel mixture. - Dave