Commercial growers move pecans this size but they have huge hydralic tree spades to get the job done. They also remove 95% of the top the year before moving the tree. In your case I'd plant new trees in the new location and get by on what you have until the new ones produce.

The Fruitnut

Yeah, I've heard a good rule of thumb is a root ball 2-3 times the size of the branches. Before you decide, you need to figure out how much that would weigh, and have you been working out?
:)

Carla in Sac