Checking ignition timing on my truck?

[Matt]

1995 Chevrolet K1500 with 5.7 TBI engine. NOT electronically controlled.

I checked the timing and noticed 4 arrows. My book says that it is supposed to be between the fourth and third (to right when looking at the front of engine). I talked to a friend and he said that you are supposed to disconnect something or other when checking timing like the old vacuum advance distributors.

I am wondering because when I checked the timing my timing was SEVERELY retarded and my truck is running like a 2 legged dog.

 

[bandit_60]

if it has a vacuum advance then hook the hose ported ( above the throttle body ) if it,s hooked straight to the intake then it can,t advance itself for more power. if your going to throw a timing light on it you will need to know where it times at, like 6 or 8 degrees. mark the timing scale at 6 or 8 whichever it calls for and there,s a line across the damper too which has to be marked. loosen the distributor, hook up the light, start your engine and let it idle, aim the light down to the damper, turn the distributor until the line is lined up with the right degree and tighten the distributor.