no definitely not.
the '93 kdx engine is still based on the old kx-engines of 87-89. In 1990 came a completely new kx-engine, where the cases and complete transmission are diferent. for the older engine you could only use the trannies of 83-89 .
in the ´93 kx250 engine you could only use the kx250-trannies from 1990- 2004 .