Description: All models. 4.3l. All models. 5.0l. Astro, Safari. 4.3l. 6 cylinder. Stamped #16197427. 5.7L. S-series. 4.3l. Exc.ZR2 Higher Wider Package. 7.4L. This part requires programming and/or special setup procedures GM Service Information describes the procedures and special tools needed to ensure proper operation in the vehicle Dictates the operation of your vehicle's vital systems, which is critical to the performance of your vehicle