The mid-to-late 70's were a busy and exciting time for the Italian company.

Fiat Trattori S.P.A had just been formed in 1974, counting four factories domestically, including the SPA factory in Turin, and the OM factory in Brescia, not forgetting four factories abroad, and six construction and assembly licenses. All having to be organized under the new company structure. 
The millionth Fiat tractor rolled of the line in 1974 as well. 
In 1975, Fiat went on a buying spree, acquiring a 20% holding in Laverda, and buying four factories from other Italian manufacturers, including the Lamborghini Trattori factory of Cento, and the Agrifull-Toselli company of Ferrara. And again in 1977, buying the Spanish tractor constructor Motransa, and Fiat's first holding in Hesston. All while developing and introducing a full line of new 80-series tractors.
In 1977, one out of ten tractor sold around the world was a Fiat tractor.

By 1979, all 80-series tractors had been revealed, and the series was such a leap forward in design and technology, that it made the rest of Fiats tractors look old in comparison. The new and modern square-cut lines reduced the appeal of the rounded styling of the Golden Ribbon models, which still made up Fiats small and basic entry-level models. Fiat therefor invested 35 billion lire in heavily updating and restyling their entry-level tractors and Vigneto/Frutteto versions, which resulted in the 70-series in 1978.

The 70-series was sold internationally and domestically as Fiat. Apart from France and North America, where it was sold under the Someca and Hesston brands respectively, though the 570 was the only one to be sold as a Hesston.

The 70-series carried over the strong and proven stressed chassis design from the Gold Ribbon series, using the same, or in the case of the 570 and 670, slightly modified engines from the 500 and 600.

The transmissions available for the 470 were a standard 6 forward and 2 reverse, with the option of a 9 forward and 3 reverse creeper transmission.
The 570 and 670 got a standard 8 forward and 2 reverse transmissions, with the option of a 12 forward and 3 reverse creeper, or a 8 forward and 8 reverse shuttle transmission. The later being the first of its kind in a Fiat tractor, which prompted Fiat to give the "H" designation to tractors with this transmission.

New linkage and draft control, together with oil bath disc brakes and other new mechanical features, not only made the entry-level tractors from Fiat advanced, but also cheaper to manufacture, do to many of the parts being shared with already fully developed 80-series tractors, in turn making Fiat able to price the 70-series very competitively.

The 470 and 570 used a three cylinder, watercooled, direct injected 8035 diesel engines. 
With a displacement of 2.590cc and 2.750cc, the 470 developed 54 hp at 2.600, and the 570 developed 58 hp at 2.650 rpm, with 170 nm at 1.400 rpm and 200 nm at 1.400 rpm respectively.

The 670 used a four cylinder, watercooled, direct injected 8045 diesel engines. 
With a displacement of 3.456cc the 670 developed 68 hp at 2.500, and 229 nm at 1.300 rpm.

The 70-series was in production at the same time as the facelifted version known as the 66-series.
This was probably do to the quick expansion that was happening at the time, with a lineup that was now sold all across the western world in different colors after the acquisition of Hesston.
At the same time Fiat was working on merging all their brands into one, which would become Fiatagri.