Normally my efficiency suffers on high gravity brews as well. Some of the issues you can't change (a higher grain bed height, for example), but you can minimize loss in a few ways:
1. Keep your mash and sparge water volumes as close to equal as you can. You obviously need to have enough water for proper conversion, but you can probably trim it down from 1.35 qts/lb to around 1 qts/lb. If you use rice hulls, it helps to stir them in immediately before run-off instead of during mash in.
2. Slow down your runoff. A slower runoff will minimize channeling in that great big grain bed. Some batch sparging folks don't see a difference in efficiency w/ runoff speed, but I sure did!
3. Be prepared to adjust with DME. In high gravity beers, a few pounds of extract won't affect the flavor profile. It may affect the color, if you're brewing something lightly colored, like a tripel or a DIPA. In this case, it may be beneficial to overshoot your gravity and add water.
4. Be prepared beforehand and adjust your recipe efficiency. As you brew more high gravity beers, the efficiency drop is easier to predict.