It has been said that the '85 transmissions are not as robust as those used previously in 123's. I have had no problems with my '85 300TD trans. Actually I had a failure in my '79 300TD trans
One thing is for certain, the '85 models shift more smoothly. That added refinement plus the CA car won't be needing air filter brackets all the time. makes it worth consideration.
You can also retrofit a federal exhaust on one if you wanted to get rid of the Nasty Trap Oxidizer.