I too use full boils on a turkey fryer. I steep my grains around 155* with some 2-row inside on the stovetop with around 1.5 qt. water per lb. grain in kind of a mini-mash for 30-60 minutes. I then strain this into the main pot and dump some more, hotter (170*) water through the strainer for a hillbilly sparge.
Takes a few more dishes, but it has helped add some distinct grain flavor to my beers, especially the wheats.