B737-800 stallspeed, flaps up, gear up and forward center of gravity at 10.000 feet:
@42.000kgs (empty) = about 126kts
@75.000kgs (MTOW) = about 174kts
Max fuel and max payload will not go together. In my airline's configuration, max fuel is 21 tons, max payload is 20 tons, MTOW = 75 tons, minus 42 tons empty weight leaves you only33 tons of total load capability.