.45
The Spark Plug gap is .045
Per Champion spark plug applications chart, the gap for 1989 Chevy 305 (5.0L) is .035.
The recommended spark plug gap on a 1996 Chevy C1500 with a V8-305 engine is .060"
.035
.035
.045"
.045
.035
0.035
0.035" ("35 mils") 0.889 mm
.045 inch , according to my Chilton book
the gap for the 1983 Chevy c10 silverado is 0.035 ("35 mils") 0.889mm