I've been trying to decide which gears to install to replace the factory 2.73s in my '89 GT vert, and I made up this chart to help me decide: - - - - - - - - - - - @70mph @140mph, Redline @5500rpm @5000rpm 2.73 = 0% shorter, 2000rpm, 4000rpm, 210mph 192mph 175mph 3.27 = 20% shorter, 2400rpm, 4800rpm, 175mph 160mph 145mph 3.55 = 30% shorter, 2600rpm, 5200rpm, 161mph 148mph 134mph 3.73 = 37% shorter, 2740rpm, 5480rpm, 153mph 140mph 128mph 4.10 = 50% shorter, 3000rpm, 6000rpm, 140mph 128mph 116mph Obviously the 2.73s are ridiculously tall. Before I'd made this chart, I figured that the 3.27s would be too tall as well, but depending on how much power my car makes, they might end up being just right. With the mods done to the car now, I'm estimating that it puts between 280-300hp to the wheels. (I'm going to the dyno in a couple of weeks with a buddy of mine, so I'll know for sure then.) The motor feels like it makes all of its power from 3000+rpm, with the biggest boost coming from about 4800rpm on up. I'm going to wager that the HP peak is around 5500rpm, which would equate out to about 160mph with 3.27 gears. I figure putting around 300hp to the wheels should be enough to get me up to 160mph in fifth with 3.27s. In addition, if I end up bolting an S-trim to this motor, I figure that'll put me at around 400rwhp, which should be enough to easily put me up to a redline-limited 175mph. Basically what I'm looking to do is spice up the car's acceleration but not go with gears so short that my top speed is redline limited. Now granted, I won't be spending much time at all near the car's top speed, but I still like its potential to be there. So you guys who have gone with 3.27s, what do you think of them? And of course, anyone else who would like to comment on my logic here is encouraged to do so.