666 (Gas) (1972-1976)

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Tractor Info


The Farmall 666 was introduced in 1972, about a year after the others in the 66 series. It followed the 656 which was selling so well, that management didn’t want to interrupt production so they delayed the release of the 666. It was available in gasoline or diesel and featured a five-speed transmission with a torque amplifier. It came with most of the features offered on the larger 66 series tractor but this model was only available with a 540 rpm PTO.

Tractor Info

Engine: IH C291

Cylinders: 6

Bore & Stroke: 3.875x4.410

RPM: 2000

CID: 291

Fuel: Gasoline

Main Fuel Tank Cap:

Aux Fuel Tank Cap:


Cooling Capacity:

Drawbar HP:

Belt PTO HP:

Weight: 7,260 lbs

Length: inches

Width: inches

Height: inches

Number of Gears: 5/1


Total Produced: 9367

1972: 7500

1973: 8200

1974: 11585

1975: 13131

1976: 15739

Location: On the right side of the clutch housing

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