What fluid should I use in my Mopar 904 tranny?

I just had a 72 904 rebuilt. The shop is closed now, so I can't ask them! D*mn it! I went to auto store and they said ATF Dex/Merc.





I just want to be sure. I sometimes wonder if it even matters???|||If the transmission was built to 1972 specs I would use Dexron/Mercron as that was an acceptable ATF to use that year. Chrysler started using ATF+3 (a synthetic fluid) in 1990 and now uses ATF+4.





Not sure what, if any damage, would occur if ATF+4 would be used in a '72 spec built 904.





And it does matter in later Chrysler transmissions, Dexron/Mercron will ruin a post '90 transmission.|||Dexron is what the factory used and will work just fine.Personally I run type F in the ones I've built for drag racing.Also on the transmission dipstick it will tell you the proper fluid to use.|||I recommend Mopar ATF 3 or ATF 4. ATF 3 is what was recommended by Chrysler. ATF 4 is the latest synthetic version and is very good.|||Dexron would be the standard fluid, type F for Fords if you want a harder shift. We used these fluids in drag cars back in the 60s and 70s.|||C-Tech is right and Mopar has a couple of good information web sites also|||ATF + 3, don't use synthetic.