Aye but there is a huge difference flying one of these crappy TP's in hot Texas and somewhere cold like Alaska.
I should imagine in the heat of texas it really was on the limits all the time.
From experence flying garretts in southern europe +30 and north scandanavia -20deg its like flying a different aircraft. That 50degs gives you another 25% torque in cruise for a start at the same level at max egt.
And 2 hours of fuel would be 1800lbs max plus 300lbs. We would need the 250 as ballast anyway for take off trim. That is very light. The drift dowm performance gets pretty horrible pretty quickly as you increase aircraft weight. On LPC's we can hold FL150 with one shut down. 1000lbs below max landing weight I struggled to hold FL50.