In a garage, not worried. I only worry on stuff with a timing belt. Rubber rots worse sitting still than staying active.
My boat will sit for extended times. A few times for several years. Stuff like new house, economy crashing, little distractions like that.
The only thing I would worry about is bad gas. And the test for bad gas is sniffing it. Take the gas cap off and take a whiff. Running on bad gas can stick rings, stick valves, and really mess up an otherwise perfectly good engine. I've seen it done too many times. Mark killed a perfectly good almost new AMC 401, took a full rebuild to fix. Worked on a Bronco that stuck a valve that hit a piston and broke the bottom of the piston letting the wrist pin rattle the cylinder wall. That was a fresh engine that was parked, went into the military and years later sold it. An old co-worker bought a car off another coworker but got lucky, the rocker arm fell out and the piston didn't bang the valve. All of them were eager to get it running on the bad gas that was in the tank.
The boat I have, use AV gas to prevent the bad gas issues.
