Well my knowledge is based only on US trucks (I would tell you that your 86 has IFS <IMG SRC="smilies/grinpimp.gif" border="0"> ) but AFAIK all of the "petrol" 22REs had 21 spline transfer cases and only the turbo trucks had 23 spine t-cases. Not sure about the diesel trucks, that is your thing over there <IMG SRC="smilies/tongue.gif" border="0"> .