Drag Racing Tech - 3.9 gears and BFG drag radials

I have a friend that has a H/C 2002 Z06 that has been able to run a 1.68 60 foot time on BFG 315-35-18's. Has anyone installed 3.9's and had a before and after comparison for a gear change? I'm curious to see if the 3.9 gears will be too much for the drag radials and would require a true slick.

He's run a best of 11.42@121.5 at 3000 feet with stock gears.

Any info

Hey Dave, its John with the 30th Ws6...

One benefit I think with using the 3.90's over the 3:42s would be that you wouldnt have to rev the stock bottom end to 7300-7400+ in order the motor to fall back to 5500, like you did when you raced it. you might only have to rev to 7000-7100 to fall into the same 5500 power band. So it would be a little easier on the stock bottom end.
just a thought.