you would need 1.33 pounds of grain to be equivalent to 1 lb of LME. wheat extract isn't 100% wheat, typically it's 40-60% wheat, but you'll be fine going with 100% wheat (but if you do have some 2-row, you'll get closer by using it for a little less than half of the weight). you'll need to mash the wheat/2row, you can't just steep it... mind you, mashing is just an extended, and controlled, steep.