Ok.
remove the air cleaner, and plug the vacuum line(s) that was connected to it, assuming you have a factory air cleaner.
Start the truck, and let it warm up to operating temp.
shut the truck off. locate the vacuum line going to the distributor (assuming you dont have computer controlled timing)disconnect the line, and plug it with a golfing tee, or drill bit.
clean your timing marks on the timing cover, and locate the 4 degree mark, left of o. you may want to mark it with white out correction fluid.
locate the distributor hold down bolt, on the intake manifold, below the distributor on the passenger side. with a 9/16 wrench, or crows foot, loosen the bolt just enough to turn by hand, but keep it snug enough so the distributor does not turn on its own.
Locate the #1 spark plug wire, its the first wire at the front of the engine, on the drivers side. connect the induction clamp from the timing light.connect the timing light clamps to the battery terminals.
start the truck, and have a friend hold the brake and put the transmission in drive.
aim the timing light at the timing scale, and you should see the timing mark on the harmonic balancer, behind the main pully. its a slot, so you cant miss it.
if it lines up with 4 you are right on. if it is right of 4(retarded), rotate the distributor slowly counter clockwise untill it lines up, if it is left of 4(advanced) rotate clockwise until lined up with 4.
put the truck in park, shut it off.
very carefully tighten the distributor hold down bolt, make ing sure not to turn the distributor.
Unplug and re install the vacuum line on the distributor.
Go for a drive and see how she feels.
