Converting from 4" to 4.5" boltpattern

Wilwood has a kit that will bolt up to 9" drum spindle. Very nice too. I've been using it for almost 3 yrs with no issues. You will have to run a 15" wheel to clear the calipers though.

http://www.wilwood.com/BrakeKitList.aspx?year=1963&make=Dodge&model=Dart