'70 440 4bbl cars with a/c used the thermostatic clutch (26" radiator)
'70 440 4bbl cars with axle packages used the viscous clutch (26" radiator)
'70 440 4bbl cars with a/c & the 3.55 axle package used the thermostatic clutch (26" radiator)

'70 440 4bbl cars without a/c or axle packages used a 1.60" lg. solid spacer & 7-blade fan (22" radiator)

* non-Superbirds