It's not a SOHC, it's an OHV with pushrods, the same one found in the Cavalier at that time. They do run forever, but like most 4 cyls you can't overheat them!! They will blow the headgasket if you get them hot. (even if you do blow the headgasket, it is a fairly cheap/easy fix due to the design of the motor.)
They are also underpowered in the S-series truck, especially with an auto and a heavy load. We ran these trucks at a company I worked for that installed satellite dishes, and they were durable and reliable, especially considering they were poorly maintained, overloaded and beat on pretty hard by the drivers.