Turbos are typically sized in milimeters
just research the turbo setup you want to replicate, take whatever size in inches and convert it to mm (inches x 25.4) , and use the one closest.
Couldn't care less what someone does with their car, since it is, after all their. car.
Rod saboury used a real 63 split window to turn into a pro street car. I love that anything to annoy the purists.