At a 30% load, roughly, I takeoff with full throttles. After I get airborne, I press "Z" to get the A/P on and holding a not too steep of a climb. I then pull the throttles back to about 70%-75% or the B-52 will reach 400+ knots. I then use the A/P trim wheels to get to about a 4000 feet per minute climb. I may have to reduce the throttles further to stop from overspeeding. At that weight the B-52 can easily reach FL400 and I reduce the throttles to 60% which I have found is just enough to keep it from overspeeding (regardless of its weight). For the percentage readings on the throttles, I have "Show cockpit ToolTips" turned ON (checked) in Options > Settings > Display > Aircraft.

Mark