Any cooling system will have to be engineered for the vehicle, since there was NO liquid cooling system in it originally. Again, a Pontiac Fiero system could be installed into the Corvair, along with all the pipes, wires, fans, radiator, transmission cooler, hoses, and other supporting parts.
A 1979-85 Olds Toronado of Cadillac El Dorado might be a better engine/transmission choice for a Corvair, but there will be no rear seat when finished.