Valuev would have never signed the contract for the fight. He isn't an idiot, he'd be a sitting duck and get battered. Lewis stops him inside 5 rounds.
Valuev by stoppage. Lewis main advantage was his size, Valuev would have ragdolled him like he did to Mc Cleen. Lewis would have gassed badly in the half part of the fight, lowering his activity to a point in wich Valuev would have easily outpointed him or even stopped his glass jaw. Lewis ducked Valuev. Considering he dropped his belt to avoid Chris Byrd, it's not difficult to understand.