Thanks for chiming in......from what I understand ,dextron III is what Mopar called for so I am assuming thats whats meant to be used......and I THINK I read somewhere that ATF +3 was superseded by ATF +4 and that Guys run the ATF +4 because it gives a slightly firmer/harder shift that the dextron III does.
FYI (and yes I know it's an old thread): Type F will give firmer shifts. Next is DexRON III.
Type 4(ATF+4) has more added friction modifiers & while keeping heat down, it would lend itself to softer shifts than DexRON III or Type F.
