On the three 71 /73's that I converted, all the Engineer (QLD) required was for the wiper arms to be extended so that the blade swept as close as possible to the top of the screen.
A simple cut and shut of the stainless arm and the articulated rod on the drivers side arm. From memory it was about 45mm.
Years ago, I contacted Canberra to clarify how the ADR Required Wiper Swept Areas were determined, after a lot of buck passing and dertermined digging, I was finally told that American DOT Standard requirements were used and then photstated in reverse to give us the right hand drive ADR Standards.
Only problem was that the datum point for the three swept area requirements continually changed due to car pillar widths all being different and also it didn't relate to centre pivot wipers, meaning it was therefore extremely hard to work out.
Engineer gave up and accepted my argument, allowing leaving them LHD and covering the maximum area by extending the arm length.
Used, FJ Holdens, all AMC cars built in Australia, early Mercedes, modern one blade Mercedes and a few others as a precedent.