At 60 deg F, a 100 lb tank can supply abt 79,100 BTU @ 25% full; … 20 Deg F, abt 43,300 BTU.
At 60 Deg F, a 400 lb tank can supply abt 185,500 BTU @ 25 % full; …20 Deg F, abt 100,700 BTU.
So, a 100 lb tank will supply a little more than half of the gas (BTU) required for the 155,000 BTU range.
While most truck setups have 100 lb tanks, we still do not know the size of tank is connected on this truck. The OP has not stated that info.