I just purchased a 97 2500 with a auto. trans. I am getting different stories on what fluids to run in the eng. and trans. One told me to run the mystic jt8 synthetic blend, another told me that i could run any oil as long as it was 15w40. In the trans, i had a dodge dealer tell me to run ATF4. My owners manual says to run ATF2 or equivalent (mercon or dextron III) . If there is a tech. that knows exactly what fluids to run, please let me know.