I'm not sure what numbers you are using for your GVW but the brochure /web/ literature numbers generally do not include options.
Any optional equipment immediately reduces the brochure numbers.
Deducting the dryweight from the GVW may leave one to believe they have 2500# available. But a large portion of the 2500# maybe eaten up by options before you even get started loading up the rig.
Brochure numbers can be very misleading. Using the factory sticker is a better way to determine CCC, cargo carrying capacity. However the sticker is not available until the rig is actually made. When shopping you need to compare brochure figures to sticker on similar model.