[Titan]

Which gasket are you referring to? The valve cover gasket?

If so, then replacing it isn't a big issue at all. You can easily do it yourself.

Now, did you check the oil level to make sure it wasn't low due to the leak? Because who knows how long the engine could have been running on low amounts of oil.

Lastly, when you say the engine was smoking, do you mean it was smoking from under the hood? As in the oil comming out the valve cover gasket being burned by the exhaust manifold or block? Or do you mean it was smoking out the tail pipe?