Thanks to the gracious offer of a couple PCMs from member GarageDodge I'll have a couple OBD2 PCMs. After looking at the wiring diagrams and pin outs from the 2001 PCM and harness as compared to my '93 OBD1 Ram Charger I believe I can splice the OBD2 connectors into the OBD1 harness and add the data link connector and downstream O2 sensor. I think the downstream O2 can be tuned out though.

I plan to do this all into the Ram Charger first and get it up and running before it all gets swapped into my '74 crew. It is a stick truck and won't have speed control so that is all stuff I won't have to worry about. Right now I'm about $150 into the harnesses I got from the donor truck. If I would have looked into this further I probably could have just cut off the 3 PCM connectors and the data link connector.

Any way I'll try to post up progress and problems. If anyone that has done this swap has any tips, tricks or warnings please post them up.