I have a 4-core radiator and still use the 7-blade Viscous clutch. I have a 160º thermostat....I have often wondered about removing the viscous fan and replacing it but I stay with the mechanical simply because it wont ever fail unless you lose a belt. I did install a 14" SPAL pusher fan on the front of the radiator and hooked up to a on/off switch. I havent run her HARD this summer but she is doing well so far in 95º weather