[dubyam]

My take is you're asking for issues downrange having it welded. That's a tough request if even a very good welder.

 

[dubyam]

When you drive 70mph on the highway, what is your engine RPM? If it's right at 2k, you have 3.36 gears. Down at 1750, you have 2.94 gears.

 

[dubyam]

Look on the snout of your rear diff for a white sticker. It will have a bar code and some numbers/letters on it. On that sticker (if it's still there and legible) the gear ratio is listed. Oddly, it's taken out to one additional significant digit, so instead of 3.36 it says 3.357 or some such.

If that doesn't work, teeth counts are the best option.

 

[dubyam]

Yes, have to be the same.