Along with fire truck applications, the Loadstar was offered as a "Schoolmaster" cowled school bus chassis.

In 1978, International introduced the medium-duty S-Series, consolidating the Loadstar and Fleetstar into a single model family.

[2] International manufactured a complete line of trucks and used few light and medium-duty vendor parts.

A conservative company, components had long production runs without model year changes.

For 1971, the Loadstar CO became the Cargostar, with a wider cab and larger grille; the model line would be produced through 1986.

The Loadstar also served as the basis for the 173/183 FC (forward control) and 183/193 RE (rear engine) stripped chassis for transit-style school buses.

Models other than semi-tractors had vacuum assisted hydraulic drum brakes standard.

There was a plan in 2012 to revive the Loadstar name for a series of heavy duty low-slung cabover trucks, to be particularly suitable for waste hauling.

[6] This Loadstar was to have offered a stainless steel cab (which would have been an industry first) to resist the corrosion associated with waste disposal, airplane refueling, and other such fields for which the truck was intended.