Is the engine output managed in 1st gear? When you say it was floored, did the engine really ramp up or did it seem bogged down? I have read of some vehicles where the computer limits the output in 1st gear to protect drive train components. This can cause problems like you experienced, or if you have a toad and are trying to pull away from a stop going up hill (remember reading a post on this situation). If the engine is being limited, it may bairly be allowed to get over the torque converter stall RPM until the vehicle is actually moving. Any extra torque requirement and a stopped vehicle won't move. You absolutly should be able to drive up a 1.5" block!
2007 Expedition EL 4x4 Tow pkg
1981 Palomino Pony, the PopUp = PUCampin! (Sold)
2006 Pioneer 180CK = (No more PUcampin!):B
Me:B DW:) and the 3 in 3 :E
DD:B 2006, DS ๐ 2007, DD :C 2008