Ouch, as far as stupid questions go... this one is pretty stupid.
Just kidding. You don't need to worry about a gasket for the casing halves. Just use some three-bond, or something of the like. Do NOT use RTV as it will run around inside your engine in solid pieces and can clog your oil pump. Be careful about smoothing out any nicks. If they are very proud, then shave them down. Otherwise, just let the threebond and the force of the bolts clamping everything together do the trick.
Camelman
