Put a BB in the line running to the EGR valve and that’s pretty much it for emissions as far as I know. But I’m no expert; I’m still in the learning process about the turbodiesels.

Your 1983 car should not have the recirculation valve that was on the 1984 + 1985 California cars & the 1985 Federal cars. Check here (search function) for information about setting the boost pressure and ALDA unit for a significant difference. Also look at this thread: http://www.peachparts.com/shopforum/showthread.php?threadid=19269

Good Luck!