Check the listing for details. OBS Chevy Trucks 1988-1998 Guide to Build, Modify & Upgrade Performance Systems. Condition: New. Listed at 28.70 USD. During the last decade, classic Chevy trucks have seen a sharp increase in popularity among the enthusiast community. From an enthusiast’s standpoint, the Task Force trucks of the 1950s and the 1967–1972 Action Line trucks are the most popular. However, the rising prices of these trucks often send budget-minded enthusiasts to the Squarebody 1973–1987 models. Now, even the Squarebody trucks are getting expensive, so enthusiasts are turning to a more modern era of classic Chevys: the Old Body Style (OBS) trucks from 1988–1998. The OBS trucks are attractive, well-rounded trucks with many creature comforts that were absent from previous generations. They are fairly affordable and plentiful, and they are new enough that well-preserved examples are attainable. In addition, they respond well to.