Purchased my PW regulators for my 77 century. Now need to decide if to make or buy a harness. What year range of GMs used the same connections for the motor and switches as my 77? Cannot picture them being very different except possibly in length of wiring or if harness included power locks. Found some connectors, seller says they fit 78 to 88 but they appear like they would fit the double, singles and the three in a row for the door locks. Thanks for any advice.