Not enough information given. Without specs on suspension and tire near impossible to guess. If the BMW has IRS, and a stock block 5.0 wheelhop and block failure are quite possible. If the f-body has stock 7 5/8" rear so failure is quite possible but looking beyond potential component failure, I lean towards the f-body for the slight power advantage, as it has been ran down the track more frequently so its launch and shiftpoints are better known (programmed), and is closer to its originally engineered setup (aolid axle, torque arm, relatively big rear fender wells) than the bmw AFAIK. And to those comparing drivers how much driving is really involved, honestly with automatic transmissions and slicks? And to the comments of the automatic and boost- aren't both cars equipped as such? I apologize if I am misinformed.
Someone should setup a poll... it appears the forum is leaning towards the bmw but it may be closer than it looks if a poll were setup.