lets beat a dead horse again..Tundra tongue weight max

Since you stated your payload was 1,555 I know you haven't weighed the truck. You must weigh the truck to know your real life payload. Fill it with fuel, put the family in, add in whatever else you would have in the bed when towing: bikes, firewood, grill, coolers, tools, etc.
Everything subtracts from payload: winches, stereo amplifiers, toolboxes, etc.
Subtract the scale weight from the GVWR, that's your payload.