What's the best weight oil to run in a Chevy 350 year round?

What's the best weight oil to run in a Chevy 350? I've been using 10w30 for years but some say it may be to heavy for winter. I need a quality year round oil.|||10w30 is fine for year around. that,s the weight of oil i use all the time and i don,t have trouble in the winter or summer. as long as your ignition and battery is strong, it will start.|||i would say that depends on the climate that you live in if its cooler yes 10w30 is fine but if its warmer 10w40 is better