Since we have forced induction we have to run wider gaps than normal.
That being said, pretty much all 'non file fit rings' are file fit.
There's nothing special about file fit rings they're just rings for a .005" bigger bore.
In your case, file fits would be a 3.835" ringset. Every thou of bore means you have to file off 3.14 thou of ring meat.
Since we run wider gaps than normal, ring filing can take a while if you don't' have a good sharp file that eats (and leaves a good finish)