I think you're going to find (especially once the tires get some heat) that the car will be harder to drive out of the corners with the wider fronts. Those who have done a good deal of track time in Vipers can tell ya that the best track times you'll get by coming in slow and accelerating as hard as possible out -- the Viper doesn't like the braking transition during cornering, so you pretty much have to completely finish braking before the turn-in. What does this have to do with front tire width? If your speed is acceptable for a neutral or mild throttle turn-in, the wider fronts are more likely to hurt your times or provoke more oversteer/snap steer than anything.
I wasn't sure what your track background was, so I apologize in advance if this is old news/remedial for you.
Regards,
Mike