Here is a screen shot from rock auto for a brand new set of dual windstar fans. I have heard that the shroud almost completely covers A-Body radiators. You will have to come up with a fan controller. But I hear they work well and are an affordable alternative. If viscous fans are so great why do All manufacturers go with electric fans on modern cars. In regards to big rigs they spend most of their time at hwy. speeds so banks of elec. would be total waste.