speedo drive gear (40t?)

If that's the actual pic of the gear, yes, it will work. I'm not sure of the years, but "earlier" Jeeps used that style of gear before things started getting more electronic oriented. Same style as I have in my ad:

[FOR SALE] - 727/904/833 speedometer pinions & related parts

I found the green, 34 tooth gears in Jeeps, but don't recall the years.