It is important to gap the spark plugs at the right size. The spark plug gap for a 1981 305 Monte Carlo is .045 inches.
The Spark Plug gap is .045
As posted on The Vehicle Emmission Control Sticker located in front of the fan shroud under the hood the spark plug gap for a 1981 4.9 liter (305 c.i.d.) is 0.060
Per Champion spark plug applications chart, the gap for 1989 Chevy 305 (5.0L) is .035.
.045
The recommended spark plug gap for a 1981 VW Rabbit is .028"
Spark plug gap is where spark plug spark discharge is designed to take place. On a conventional spark plug, it is the area between the center and the ground electrode.
.045
.045"
.035
.035
.45