It won't kill your engine but I'd run a 10W30 if you are using dino oil. You can get away with a lighter oil if running synthetic… IMHO of course.
Living the dream behind the Cheddar Curtain
'88 F-350 Crew Cab Dually, 460 Fuel Squeezer, C-6, 4.10's
'97 Ram 1500, '99 Jeep Grand Cherokee. '90 Buick Park Ave.
Plus an old dirt race car.