318 to 440 wiring ???????

No I have automatic trans. I did some checking today at the local NAPA store and found out that the sender that is broke is for the back-up lights (no big deal). But they are different, a 727 plug has 3 pronge hook-up and a 904 has 2-pronge not to mention they are different in size the 904 is smaller and won't screw in. Which still leaves my problem with the trans. wiring harness not fitting a 727 3-prong sender. Do you know of any other wiring harness problems in the motor compartment converting the 318 harness to a 440 motor? Thanks Dave!!!!!!!!!!