D 250 Pickup V8-360 5.9L (1984)
Drive Belt: Specifications
A belt in operation for 15 minutes is considered a used belt.
Strand Tension method: Use gauge. Measurements are in pounds. Used belts, 70; New belts, 120.
Deflection method: One-fourth to one-half of a inch or 6-12 millimeters with 10 lbs. of force applied at midpoint of belt.