If the timing belt breaks on my 1991 dodge stealth dual overhead cam 24 valve Mitsubishi engine will the valves bend?

It's possible, but if you turned the engine off/put the tranny in neutral immediatly, you should be ok. Replace the belt and turn the engine over a couple of times (avoid starting, if possible) with a friend standing over/near the engine. If they don't hear and wierd noises (odd ticks or clicks), start her up. Listen carefully, if you don't hear anything out of the ordinary - you should be good to go.