Third gear is almost done at the end of a 1/4 mile at around 100 mph. I've almost always gone through the traps in 3rd, but have tried short shifting into 4th at around 85-90 mph, but haven't seen any improvement in mph and I think I'm hurting my ET by about .05 second because of the extra shift.
Swap to 3.73 or 4.10 gears and you'll definitely be using 4th gear, however.
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