yo J,
the Rotunda cable should fit because all Break Out Boxes made by OTC, Thexton, Ford (Rotunda), & others need the connectors to be exactly the same to fit the EEC IV module. But BO panel overlays appear to me to be different; you will need the correct overlay. Contact seller and ask.
But you can do quite a few tests w/Out the BO Box; go to the EEC pin instead; for instance, for the E4OD MLPS; "...MLP voltage (ignition on) should be within 20% of these specifications. Note It is recommended that you use a break-out box. If a break-out box is not available, you will need to pierce the wires to pins 30 and 46 for these tests. NOTE: Click on image to make it larger. (Step 3) Check the resistance of the MLPS: The resistance of the MLPS (pins 30 and 46) should change-in increments-with the position of the manual lever (figure 4). Note If this test is being done with a break-out box, disconnect the computer first (make sure the ignition is off). If this test is being done without a break-out box, disconnect the MLPS from the vehicle harness...