Flex a lite has a 6 blade 19", also a 18" 7 blade HD fan, summit race & 4818 Flexalite worked great on my 512 ac street car, I now have dual electric,
Flex-a-lite 101571 - Flex-A-Lite 7-Blade Fans

Fan, Flex-Type, 7-Blade, Clockwise, 18.25 in. Diameter, Stainless Steel Blades/Steel Hub, Universal, Each

Part Number: FLX-4818 it moves a lot of air, That said I run the smaller water pump pulley, my car has ac