You can find wiring diagrams for the 1991 Chevrolet K1500 1/2 ton pickup with 4-wheel drive and 5.7-liter 8-cylinder on the AutoZone website. You can also find fluid capacities, torque specs, and repair information and instructions.
The wiring diagram from the distributor cap to the spark plugs for firing order for a 93 Chevy Caprice 5.7 liter engine is found at Wiring4cars. You can search the site by vehicle year, make, and model.
A picture diagram of the drive belt routing is suppose to be on either the underside of the hood, close to the latch assemble or on the radiator support panel. also it as the same routing as a Toyota Corolla 1.6 liter 1987-1992.