Another speedometer gear question

[OEM1984CJ7]

I have read just about every archive on the speedo gears and cannot find the answer. I have the 1984 CJ7 with stock 2.73 axles running 30 x 9.50 tires that are 29.5 diameter. I originally had the Dana 300 that had the three different positions speedo housing on the 26-31 setting and a red 26 tooth gear. I bought another Dana 300 to swap it with due to bad/hard shifting and this Dana 300 has the speedo housing with the 21/25 on it and there is a 25 tooth yellow gear in it.

The two gears are different size and tooth spacing and do not look interchangable. I am trying to find out what was factory with the 215/75 tires and get it close with my 30 x 9.50's. I cannot find any tooth gear chart with 2.73 axle gears on it. Help please.

What should be stock? Both?

 

[BusaDave9]

If you want an accurate speedometer work with percentages.
Install your TCase and then test your speedometer. You can do this by testing your odometer and comparing it to the mile markers at the side of a highway. Or test it by driving by one of those radar speedometer signs that say how fast you are going.
If your speedometer is 7% too high then get a speedometer gear with 7% more teeth.

 

[Old Dog]

My 83 had 2:73's and came with the red 26 tooth gear.