TT,
The oil will lubricate, and it won't kill the new engine. I would consider it on the shy side unless it gets quite cold in Maryland.
I have actually never seen 5w-20...maybe they don't market it in the warmer areas.
If it were my rig, I would run the 5w-20 for as few miles as my pocketbook could stand, then change it. With a new engine, there are bound to be goodies in the oil, and a quick change wouldn't hurt anything.
Did the rebuilder recommend the 10w-30 oil? What is an average temperature in your area.
Stuart
