Access Original Soft Roll-Up Tonneau Cover for 1988-2000 Chevrolet C/K Pickup / GMC C/K Pickup (GM 6'6" Box, Fleetside box)

Here's the short version. Follow Access's install sheet (below) for your truck's exact clamp positions, plus any special sheet your truck needs.

1. Clamp the side rails. Set each rail against the inside lip of the bed, pushed forward to the front wall with the nylon strike at the tailgate end (long beds join the two rail sections first). Hold the front flush with the top of the bed, then clamp from front to back with the clamp teeth in the rail grooves and the rail level, and torque each clamp to 20 ft-lb or the value on your truck's special sheet.
2. Fit the bulkhead seal gasket. With the air and surface above 60°F, wipe the top of the front wall with the alcohol pad. Peel and stick the gasket from the front of one rail to the opposite corner, raised side along the inside edge of the bed, and trim it to length.
3. Add the rear seals. Clean the underside of each rail end, mark and notch the rear seal's leg, then stick a seal to the tailgate end of both rails.
4. Attach the tension adjusters. Set the pre-rolled cover on the tailgate with the front bar facing up. Thread the left (L) and right (R) adjusters onto the front bar and leave both bolts loose.
5. Mount the cover to the rails. Set the cover at the front of the bed and roll the front bar onto the rails with the vinyl flap tucked under it. Bolt each adjuster under its side rail without turning the dial, center the front bar between the rails, then tighten the adjuster bolts.
6. Close, check and fine-tune. Unroll the cover and press the rear bar into the strikes. Close the tailgate and raise or lower the rails at the rear until the tailgate fits snug under the rear bar, re-check the clamp torque, even out the tension with the dials (counterclockwise tightens) and seal both sides with the hook-and-loop.