There's an INTERNATIONAL WorkStar 7300, 7400, 7500 & 7600 Operator's Manual PDF above the page.
In the 1990s, International Navistar entered with a new gamut of different classes, which had a four-digit number.
The 1000 series was a chassis for the city's semi-hood layout vans.
The next, 2000, is a simplified chassis with a gross weight of 13–33 tons with motors with a capacity of 230–435 hp with steel cabs, they were usually used as airborne or dump trucks.
The 3000 series was also a chassis, this time for school buses.
The newly developed hood series 4000 was distinguished by a plastic “aerodynamic” plumage. It was offered in different versions with a gross weight of 16–25 tons and was equipped with diesel engines with a capacity of 175–300 hp.
The main "highlight" of the program, the hood "builders" Paystar, continued the 5000 series. Repeatedly updated, they were produced with different hoods and cabs, had a total mass of 16–38 tons and engine power of 275–525 hp.
The next series, 6000, was reserved for full-blown buses of its own production, but was never produced.
The 7000 series was a simplified biaxial urban tractor based on the 4000 series.
The new 8000 series - regional tractors, mainly with their own diesel engines with a capacity of 195-430 hp.