Best there would be serpentine belt 5 grove is the same has having 5 belts. But flanges would be easy, just some thin metal bolted or riveted on the side of the pulley................CurtI still don't see it working without flanges on the pulleys. Just an RCH of misalignment and the belt is gonna throw itself off. The flanged tensioner isn't enough to keep it in line. I think a better way would be a multi-V belt with a stiff tension spring to prevent slipping.