Had the fastest car every round with dual gear diffs last night. After breaking in some Sweep 32s I went to AE60 in the rear and eraser/500k up front.
I also flipped the upper deck, and only used 2 screws at the very front and back. I had some large countersunk washers for extra clamping surface area. I had PLENTY of traction all night and didn't lose any steering. I'll post a picture later........ BUT.......
Doing some testing after the mains, my friend Jonesy rear-ended me on the backstretch (he was testing his mod car) and so far I need to replace 3 screws, my Tornado fan, and the upper deck (snapped in 2).
The car also drove MUCH smoother with Solaris 32s. Sweeps simply grabbed too much without causing a push.