As you can see from the title, I have a 1985 L series with an EA82 in it and I've got some clicking from the LH head, which I'm pretty certain is the valves, sticky lifters or something. I've had the car for over a year, but only had it registered on the road a short while. Before I had it, it had been sitting for about a year. When I first got it the clicking was really bad, but with a bit of use it stopped. Now it's back again

Now I know my way around a little bit, but I'm no pro mechanic. Can you guys help me out with a few things I could try to help stop the valve noise?
Also, could my L sustain any damage from this clicking over a long period of time?
Thanks,
Tom
PS. Awesome forum, good to see a site devoted to the Subaru in aussie!