285 is what I've memorized and what I try my best to never get slower than, Bads 280 seems right if not on the conservative side... mind you, expect to experience a violent snap to the left under that much laden weight (100% fuel) and torque (mil power at SL), while trying to pull 6gs... it's not the easiest thing to do in a Dora, just be careful jumping into it with a ham-fist, unless you're ready/prepared to counter the strong desire for the left wing to snap low (and assuming you're alrady cruising at SL) you're probabley going to put her in the drink a few times pulling back too hard or abruptly.