To find the correct size, you need to:
1. Look at your calipers: The easiest way is to remove one of the caliper bolts and take it to an auto parts store. They have bolt sizing charts and can match it for you.
2. Consult a repair manual: A repair manual specific to your 1996 Chevy S10 (year and model are crucial) will list the correct bolt sizes for your vehicle's brake system.
3. Check online parts databases: Websites like AutoZone, Advance Auto Parts, or RockAuto allow you to enter your vehicle's details (year, make, model, and engine) and view diagrams showing the brake caliper and listing the bolt sizes. However, double-check the information before ordering parts.
Do not attempt to guess the bolt size. Using the wrong size could damage the caliper or even lead to brake failure, which is extremely dangerous. Always be certain of your measurements before working on your brakes.