drewsky

A 3:55 to 3:73 is immediately going to make you wish you had more. You won't even feel the difference really. I debated between the 4:10-3:73 for months. You won't get much worst gas mileage, about 1mpg less overall.. It's soooo worth it for what it does to the car. You said yourself everyone says go ahead with the 4:10's and I'm adding to the list! DO IT you will have no regrets!

retfr8flyr

With the 6R80 automatic, if you want the best 1/4 mile times then install either 3.15 or 3.31 gears. Anything more is just a waste of time due to the gearing in the 6R, hell it's got a 4.17 first gear. Go with 3.15's if you're basically stock and 3.31's if you have a few bolt on's and a CAI. This will have you going through the traps at the top of 3rd gear. You don't want to be shifting into 4th gear, not only does it cost you ET but 4th is a weaker gear with less clutch packs then 1-3rd gears.

Also get your tune from Mike Rousch at Mid Atlantic Performance 1-804-332-6685 - Email: Mike@MidAtlanticPerformance.net. Mike has really figured out the new 6R and 5.0 combination in the new Mustangs. His personal, naturally aspirated, 5.0 has been 11.16@123 with a 3.15 gear and 275/50/15 drag radials.