The problem is famous enough to be in a magazine: http://www.import-car.com/ic/ic40024.htm
Mine, two years ago, broke one valve and took out a piston. I'm just now putting in a short block and correcting all the screw-ups my "low-cost independent" incorporated in repairing it. I've drilled out eight socket heads, found the intake gasket was leaking and discovered broken spring shims in one head. Make sure you get references from someone who has had major work done, not just tune-ups. Good luck. By the way, Auto Sports Unlimited in Zeeland, MI, offers this engine remanufactured at a reasonable cost as well as remanned heads. Compare it against repair of yours. I found out I could have replaced mine cheaper.