Dan:

Great job, idle issues can be a pain to resolve. Although Kellogs and Rice Chex gaskets have been known to work for decades, I would recommend getting a real gasket to avoid air leaks as the cardboard compresses and the torque on the mounting nuts drops "as a result".

jorrell

ps. If you are doing one ball joint, go ahead and do both then have the car aligned once, rather than twice... er, unless you already replaced the other one!