The order for the Mister Softee ice cream trucks specified that they be built on a 1-ton Ford commercial truck chassis, and utilize their heavy duty 262 cubic inch inline six cylinder engine.
The trucks would eventually be fitted with a stainless counter, functional sink with potable water, a generator, and soft serve / freezer machine. The mobile kitchen would be able to serve several hundred people with fresh food without having to replenish supplies back at headquarters.
It was this capability that made the Mister Softee appealing to Civil Defense coordinators during the cold war era. Mister Softee, it appears, would soon roll up his sleeves and help make America safer.