Most of them will run anywhere from 5 to 12 volts. The lower voltage just slows the fan.
74 Challenger, bought it new. In 1978 I replaced the original 318 with a 446 and 727. Mild cam, Jardine headers, and Holley Sniper EFI. New engine! 511" RB, Edelbrock Performer RPM heads, Eagle rotating assy, Comp hyd roller cam, Doug's 2" headers.
