Ah gotcha, didn't realize it was you from the other post.
I still have the 3.46 gears. They are great for the street and gas mileage. I've found them great for roll racing.
3.91's I've heard really wake the car up. A lot of people say they make it more fun to drive. You'll have to shift more and you might have traction issues in first gear. At the track 3.91's really help the M6 goats come out of the hole without bogging. Especially with sticky tires. These gears are going to be more at home at the drag strip for a lightly modded GTO then 3.46 or 3.73's. If your going with a decent size cam soon 3.91's would help the car down low and get the motor to the power band sooner so the cam can pull up top. I've really wanted to try these gears for a long time.
I think 3.73's are a happy medium. You get a little more grunt downlow to help get the heavy car moving compared to 3.46. Gas milage won't be too far off what it is now. I think these gears would be more at home on a road coarse then 3.91's which I'm setting the car up for. And still help with getting off the line at the drag strip which i like to do occasionally. I think they would also match up better with a smaller cam then the 3.91's as a smaller cam usually has more torque down down low. After talking to a GTO diff builder expert, If i decide to do gears these are the ones I would prolly get.
2006 GTO M6
Motor - Stock with Vararam
Bunch of suspension
Bunch of brakes
12.81 @ 110.6 2.03 60'
Last edited by GTO44; 08-26-2016 at 10:21 AM.