7 material differences · fewer than 12
Tractor oneInternational Harvester Farmall 7061963–1967No measured PTO figureTractor twoInternational Harvester 6661972–1976No measured PTO figure
Which should you choose?
We will not advise between these two machines, because they were not built in overlapping years (1963–1967; 1972–1976). The figures below are side by side so you can judge them yourself; each says whether it was measured, claimed or declared by its source.
Field by field
7 material differences · 6 fields identical or within 5%, which is not counted as material
| Field | Farmall 706 | 666 | Gap |
|---|---|---|---|
| Engine | |||
| Engine power, claimed claimed | 66.1 hp | 66.1 hp | — |
| Engine declared | INTERNATIONAL HARVESTER C-263 or C-291 | INTERNATIONAL HARVESTER C-291 | differs |
| Transmission | |||
| Top speed declared | 18.6 mph · 30 km/h | 18.6 mph · 30 km/h | — |
| Clutch declared | Pedal-operated dry single-plate clutch | Pedal-operated dry single-plate clutch | — |
| Hydraulics & hitch | |||
| Pump flow declared | 12.0 gpm · 45.5 L/min | 12.0 gpm · 45.5 L/min | — |
| Rear PTO speeds declared | 540/1000 rpm | 540 rpm | differs |
| Weight & dimensions | |||
| Unladen weight declared | 8,699 lb · 3,946 kg | 8,199 lb · 3,719 kg | +6% Farmall 706 |
| Wheelbase declared | 97.5 in · 2,477 mm | 103.0 in · 2,616 mm | +6% 666 |
| Length declared | 157.0 in · 3,988 mm | 161.0 in · 4,089 mm | — |
| Width declared | 92.0 in · 2,337 mm | 87.0 in · 2,210 mm | +6% Farmall 706 |
| Ground clearance declared | 21.0 in · 533 mm | 21.0 in · 533 mm | — |
| Turning radius, braked declared | 9.2 ft · 2.82 m | 12.0 ft · 3.66 m | +30% 666 |
| Fuel tank declared | 132.1 qt · 125.0 L | 123.9 qt · 117.3 L | +7% Farmall 706 |
Height is not in this table. It is not one measurement: the sources measure it to different points — over the cab on some machines, over the steering wheel or the exhaust on others — and the same tractor measured two ways can differ by most of a metre. It appears here only when both machines' figures carry the point they were measured to and it is the same point, which is not the case for these two. Each machine's own page prints its height as its source gives it.
International Harvester Farmall 706 sources
- Source: Traktorenlexikon, “Farmall Farmall 706”
- Source: Traktorenlexikon, “IHC 706”
International Harvester 666 sources
- Source: Traktorenlexikon, “IHC 666”
- Source: Traktorenlexikon, “Farmall Farmall 756”
- Source: Traktorenlexikon, “Farmall Farmall 666”