I have a 92 rs that had stock a 3.1 v6. The 350 carb conversion has been great, but I know I can put out more with all the mods to the engine. I believe I still have 3.23 gears...that would be an appropriate rear to replace it with so I have full potential to work with?

 

Depends greatly on your intended use. But generally;

3.23s behind a 350 is a great daily driver mix, it will still give you a decent launch without effecting your highway mileage too much. 3.42 is about as much gear as you want to go without sacrificing mpg too much. Alternatively, if you want to build a street/strip car, you would want to be between 3.42 and 3.73. This will still give you some street manners, but far more initial launch. The lower you go in your gearing the more your mileage will suffer, and your top speed will also decrease slightly. Finally, if you're building an all out strip car, go with 4.11 or lower. this is pretty much worthless on the street for anything but pure stoplight to stoplight fun, as it will "pass anything but a gas station".

Lastly, look into a limited slip for any of these uses. It will help to translate the power to the ground much more efficiently over the open differential, and allow a modicum of traction control in daily driving.

Keep in mind all these suggestions are for the stock rear ends. There are 3 different basic 10-bolt rear ends, and you are limited in what size gears fit in each (as far as factory gears go). You have many choices when it comes to aftermarket, and again, depending on your intended use might also look into better suspension to give the car more hookup in a hard launch, and vastly improved and strengthened rear end components.

 

Thanks for the greatly informative reply!

 

Not a prob. There's an excellent stick in this section about the 10-Bolt rear, look thru it for more info. On a side note, the 4th gen rears are a direct bolt in, and frequently have between 2.73 and 3.42 gearing available, depending on application. The V8 cars also usually featured limited slip, and rear disc brakes (11.5" with PBR calipers). I have a '95 Z/28 rear with discs and 2.73 limited slip in my '83 Z/28. The only fitment issues are the parking brake cables (which there are workarounds for), and the earlier Thirdgens still used standard threads instead of Metric on the brake line connections, but this is also fixable. The 4th gen rears are 2" wider on each side, so different offset wheels must be used or they will stick out significantly past the wheel wells.

 

How has your experience been with the 2.73 gears? Less launch, more top speed?

 

I have a TPI 333 (.040 over 327) with a LT4 Hot Cam and a LOT of work, so I still launch pretty good even with a factory IROC-Z stall and the 2.73s. I want to upgrade to between 3.23s and 3.42s, but not for harder launch, but better in-town fuel economy. I'm getting 27mpg right now on the highway with the 2.73s, but in town I'm as low as 16-18. 3.23s or lower would be a better match for my engine, sure I'll lose a couple of mpg in highway driving, but since 80% of my driving is below 45mph in town and stoplight to stoplight, the lower gears will help me immensely to raise my city mpg.