1990 chevy silverado 5.7 liter distributor diagram

SOURCE: distributor cap and rotor location on chevy silverado

Most chevy 5.3 do not use a cap and rotor. Most have single coil per spark plug and wire. Trace spark plug wires to coil usually above the valve cover.

SOURCE: 1990 chevy 350 distributor wiring diagram and firing order

The firing order is 1-8-4-3-6-5-7-2.
The distributor rotates in a clockwise direction. The engine must be on the compression stroke on the #1 cylinder. Line up the timing marks. Remove the cap and the rotor should be pointing to approximately the 5 o'clock position.

Good Luck

SOURCE: how to replace spark plugs on 2005 chevy silverado

spark plug wrench and alot of patients with the very back ones hard to get to

SOURCE: need vacuum line diagram for 1990 Chevy Silverado

The vacuum diagram for the truck should be printed on a factory sticker right next to the hood latch inside the engine compartment. If its missing or ruined you could try looking inside a Chilton or Haynes manual.

SOURCE: I need a vacuum diagram

vacuum cannister