i don't think i've seen obd0-obd2 conversion harnesses, but boomslang will make one, or you can get an obd0-1 conversion harness and obd1-obd2a conversion harness and connect them together...boomslang has both of those. he will make custom harness for the obd0-1, but look at the pricing vs. using the other 2 together.

don't forget you'll need to upgrade to an obd1 or obd2 dist and wire that in or get the dist jumper harness to convert from obd0 as well.