It's all down to gearing. If the ED had the same ratios as the VN, it would probably beat you. Thankfully your VN has a 3.06:1 first gear while the falcon has a rediculously tall 2.39:1 for first. While the commodore has a slightly taller diff ratio, (3.08:1 versus 3.23:1 for the standard falcon) in terms of final drive ratio in first the commodore is still streets ahead. Second gear for the commo is 1.63:1, for the falcon it's 1.45:1, taking into account the slight diff ratio difference there's bugger all difference between the two final ratios in second.
Contrary to popular opinion the commodores off the mark advantage is not due to it's "superior low down power" aka torque. In reality the e-series falcon 6 makes a fair bit more torque than the buick through most of the rev range. (Although VN series ones and other comodores running early tunes with the bellmouth removed may well have a bit more grunt down the bottom end) Time and time again it has been shown that the commodore will destroy the falcon through first (due to it's massive gearing advantage, then through second the falcon will either hold position or gain slightly, and then in third where the falcon has a slight gearing adantage (basically level pegging though) that allows it to put it's torque advantage to good use it hauls the commodore back in. (although by the time you've got the right boot on the floorboards in third you're doing fairly silly speeds and would definitely wanna be on a racetrack or private road)
To summarise, to legal speeds, you should beat him with fair ease. Unless one or both of you is running a manual in which case things become more complicated. Don't let us know how it goes, because street racing is bad mmkay?
EDIT: ahhh crap, missed the bit that said it was a manual. I honestly can't be arsed chasing down the ford T5 ratios. Suffice it to say that the manuals are faster than the auto's. You'll probably still win unless he's one of these crazy buggers who'll ride it off the line and flat shift just for the sake of winning. Even if he is, he'll be the one replacing his clutch after a few runs.