I have a 76 Dodge with the A-230 Manual Transmission, 3-speed on the column. I am thinking about changing the fluid. The factory manual says to use Dexron ATF fluid. Will the newer high-tech Dexron III to VI fluids be compatible. Most of the new fluids are all synthetics. Will that be ok to pour in. I did some on-line searching and Royal Purple makes an ATF fluid that is compatible with older Chrysler transmissions that took the original Dexron. Lucas Oil and Castrol seem to also make a similar fluid. I have owned the van for 40 years and the fluid has never been changed, but still looks clean. I am doing some shifter linkage repair and thought this might be a good time to refresh the fluid.