Wups.
I didn't look up the part number. I thought it was obd2 reader and that's what prompted my original (post number 2)
Sorry

 

You want a Moates Quarterhorse, it's a little module that plugs into the J3 port on the back of the EEC-4 PCM and overrides the internal PROM. With software like Binary Editor on your laptop you can then edit and save custom calibrations on the modules flash or EEPROM memory as well as see and datalog all PCM sensor inputs and control calculations like fuel trims and ignition advance in real time. The only catch with this setup is you need a Definition file for your specific PCM which is a map of where everything is located within the computers memory, and that isn't available for all the SD computers since they generally aren't used in performance vehicles, so you either have to find someone with the tools and skills to generate the file or switch to a PCM that has already been decoded.