Moisture in your oil is acid on bearings. New engine I would drop the oil in Fall. Dry cold up here so not going to drop it in Spring.

500 mi 1st year on your engine is good but 1000 mi would be better. I doubt turning it on once a month over the winter would not be a good alternative to an additional 500 driving miles. My 1st rebuild failed just before 1000 mi. Your chances of failure is very low though. I was very impressed with your build. Well planned and executed and budget driven project. You need a healthy budget to get the project down right but just throwing money at it does not guarantee success.

Guys & Gals: Put something in your cars to keep rodents out in winter. The buggers caused a lot of damage to my car. What do you guys use? I've used moth balls in the past.