Truck Bed Slide

When they refer to the payload and towing capacity - do they mean one or the other? My truck has a towing weight of 6,600 individual and a payload of 1840. If I tow 6600 pounds, how much weight I can get in bed together? I know the gear / tools / gas / remove people from the payload, but what about the weight of towing?

10-15% of the weight of the trailer tongue would be counted toward the payload. Thus, 6600 x 0.15 = 990. So you're already over half way to you max payload.

just load and go you do reach the limit of thinking to many

If it is a Ford be careful, if it is a Chevrolet are light to medium loads OK if it is a GB Dodge and Loadum