When in doubt, refer to the FSM. The new MOPAR ATF+4 will work fine, but it has detergents that the older transmissions may not need. PLUS it costs more. The Dexron/Mercon is the default replacement for the Dexron, Dexron II and Dexron/Mercon. Mopar Action recommended Type F for better shift quality and less slippage. I've often wondered if it is a problem to switch types on a used trans. It is nearly impossible to fully evacuate the old fluid without total teardown. Would a 95% to 5% mix cause trouble?