I took the old gear out of my car a while ago and im tryin to figure out what gear ratio it is. Im not gunna count the teeth, but i did get the number stamped on the side off of it. Some of them were a little hard to read, so I guessed, mainly the letters, but i got most of them. 327e6za136cb my best guess would say that means its a 3.27? Correct me if im wrong.

 

Try this calculator here. If you know your speed, know your RPM, and know your tire size, then you can figure out what gear your in.

Lets say you do X-MPH in 4th gear at 3000 RPM with Y-tire size. So plug in your known RPM, known tire size, and known transmission type. Then just take a guess at the gear. (Guess 3.27 or 2.72 for example.) It will tell you how fast you would be going if you had 3.27 gears in your setup. If the number it gives you matches your actual speed for 3000 RPM in that gear, then you know you guessed the right gear. If the speed it gives you is lower than your actual speed, pick ahigher gear. If it tells you you are gonig faster than you really are, tehn pick a slower gear.

In reality, tehre are only a few options and it shouldnt take long to fgure it out. Just try the standard ones that are common for stock and aftermarket. (4.10, 3.73, 3.55, 3.27, 2.73, etc)

 

umm quick q... i just calculated my car from what i have right now 2.73 and then with 3.73's which i'm gonna be getting and there was a 680 rpm increase... is this about right?

 

Yup, lol. Welcome to the lovely world of 3.73s. It's a big jump from 2.73 to 3.73 gears. You'll definately feel teh difference, but expect your engineto work a little ahrder to get to the same speed. But look on the right side... First, you accellerate MUCH faster. And second, because you accelerate much faster, you get to your powerband much faster The down side is you are going to burn more gas due to the higher RPM.

 

They are NOT in the car. I blew out my diff a couple of years ago and i picked up a whole rear end and then swapped my 4.10s over. So I dont know what ratio it is, because I never drove the car with those in it.

 

great... my gas mileage is decent (usually like 18 in the city) but that's after all the mods i've made.