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Old 03-09-2013, 06:50 AM
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No. The Chevy car 12 bolt uses a 2 series for 2.56 and 2.73 gears, a 3 series for 3.07 to 3.73 gears and a 4 series for 3.91 to 6.xx gears. There are special 3.73 gears that fit the 4 series and 3.91, 4.10, 4.56 and 4.88 gears that fit the 3 series. There are no 3.73 gears that fit the 2 series differential. You will have to get a 3 series Eaton Posi to use with the 3.73 gears, or you can find a 3 series Eaton Posi case and transfer all of the internal parts from your 2 series into it.

I know that someone is going to mention a ring gear spacer, so I might as well cover that too. Yes, you can use a spacer to put the 3.73 gears on your 2 series Eaton. Is it a good idea? NO! There are several problems that come up when using a spacer. The first one is that the ring gear no longer fits tight on the differential and will not center properly. This causes problems with the gear contact, backlash and other things. Another problem is that the ring gear bolts tend to shear off when using a spacer. I've seen these problems several times and I can not recommend using the spacer, even for a street car. Just do it right the first time and save yourself some money in the long run.
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