Speedometer gears for pre-92 YJ
I hope this little bit of information is helpful to someone here. I had some trouble finding the correct speedometer gear for my '89 with the cable-driven speed. The long-shaft style gear is not stocked at Quadratec and can be tough to find at Jeep dealers. I didn't want to convert to an electronic sender, though that is an option.
Thankfully there is another, and usually cheaper, option. Many Mopar trucks and muscle cars used the exact same gears. I was able to find one on eBay for $15. Compared to the original Jeep gear, the shaft is identical. Search for "mopar speedometer gear" on eBay and you'll see a half dozen or so, most of which will fit. Yearone and other Mopar muscle restoration companies have them as well. Look for ones that fit the 727, 883, 904, and 998 transmissions to start.
I'll try to find some Mopar part numbers. If anyone else knows them please post.
Note: I'm talking about the long-shaft speedometer gears for cable-driven speedometers, not the newer short-shaft style for electric speedos. There was some overlap in years where some cable-driven speedos used short-shaft gears, and vice versa.