How do I set the engine timing for my chevy truck?

The LO3 was the "low output" 305 in³/ 5.0L (compared to the TPI 305). It produced 170 hp and 255 ft·lbf of torque (185 HP @ 4,400 / 275 TQ @ 2,400 in 1993-1995 GM trucks). The 305 dropped the Computer-controlled carburetor and received the fuel-injected TBI (throttle-body injection). The TBI unit consisted of two barrels, much like those of a two barrel carb, but instead of "jets", there was a fuel-injector placed above each barrel, resulting in a 2-barrel, 2-injector setup. The TBI uses a unique injector firing scheme, for every rotation of the engine, each injector fired twice.