I have a 2003 Silverado 4WD with a 5300 Vortec v8 engine and factory towing package. Runs like new so I don't need to scale back numbers to account for age.

I can't seem to figure out what my max payload is. The GVRW is 6400 pounds, but I don't know the curb weight.

Also, I don't know how the 3" lift kit and wide offroad tires affect the GVRW. I'd think I could haul more with bigger tires, but the engine and breaks still have to do the work.

It's an extended cab (suicide doors, not full four door) with a 6.5' bed.

Anyone have any suggestions? I'm hauling railroad ties for landscaping, and they're heavy suckers.