If you're confident it won't get below freezing you don't have to drain it.
Nothing gained by running it once a month either. It'll take 20 years for a
cast iron block to rust enough to even begin to be an issue.

I'm pretty confident my garage, surrounded on three of five sides by the
house never gets very cold either but I drain my engine anyway. It only
takes about 10 minutes to pull the plugs and disconnect the hose on the
power steering cooler. And 10 minutes in the spring to put it back.

wrote in message
ups.com...
I crammed my 19' boat (3.0L alpha) into my enclosed, insulated garage.

Do I need to fully winterize it? The garage stays in the mid-50's
during the winter months. I have a trickle charger to maintain the
battery. I can also pull it out monthly and run it in the driveway at
idle temp.

What do you think?