How to find out what rearend gears you have, plus axle spline q

I'd like to find out what my rear-end gears are. I know there's something where you turn the wheel a certain amount of times and see how many times the driveshaft turns. Can someone tell me exactly how to do this?

Also, I've gotta find out how many splines my axle is, so I can order my posi-unit for my differentail. Is there anyway to do this besides pulling the axles?

Thanks. :)

Is there anyway to do this besides pulling the axles?
No, not really. No matter what the RPO codes, numbers stamped on the axle tube, spin tire while watching driveshaft, etc. says, you never know what the previous owner(s) could have done.

Just pull the cover off, and look on the side of the ring gear, somewhere on there it should have a ratio stamped on it, like 41:12. Divide the large number by the small number, and that's your gear ratio. You could also just count the number of teeth on the ring gear and the pinion gear and divide that.

And, as for the axle splines, just pull one out since your already in there and count them ;) . I know it seems stupid to do that just to be 100% sure, but better safe than sorry, right? :D

Put the rear of the car in the air. Turn the rear wheel one revolution and count the number of revolutions the driveshaft turns. It should get you close enough to tell what ratio you have.

Stock axles are 28 spline.

So for every one turn of the wheel, the driveshaft should trun a certain amount of times depending on what gears I have? Does it matter if I do the right or left wheel, because this is not a posi car?

The easiest way to find it out is to locate your RPO codes and I'm not completely sure which code it is going to be but enter it on this website to find out what the rear gear is. http://www.camarosource.ca/php/camaro_info_db/index.php?act=decoding&year=1996&tm=1

Stock axles are 28 spline.
If the rear end in your car is still the stock unit, it will have 26 spline axles.

82-88 F-Bodies got 26 spline axles, 89 was the changeover year (most 89s got 26 spline axles though), and 90-92 F-Bodies got 28 spline axles.

You can use the calculator in my sig to figure out what you have by putting in the gears you think you have and see if the RPM is the same when compared to the gear/speed indicated in the results...

Also you can estimate by marking the drive shaft and spinning the tire one full revolution while watching the driveshaft rotate and count/estimate how many times it rotated.. for example if it rotates just under 3.5 time then you more then likely have 3.42's, and if it rotates about 3 and 3/4 time then you probably have 3.73, etc. etc.

It does not mater what way you rotate the tire, because that will just cause the driveshaft to rotate in the opposite direction.

Hope this helps.