'73 up drum to disc conversion track width change

Here we go again with whether or not you need to move the perches.
I've done it without moving them and it works with no issues, even under hard launch at the 1/8 mile.
For the purposes of this thread- the point is that particular axle puts the rear track even with the factory disk brake front track.
However, it's no concern for the OP as he has other plans anyway.