The question is, will mini-tubbing your car make it illegal for any class you might want to race in.
If you are just wanting to do it on a street car, mini-tub it. If you want the widest possible D.O.T. tire for a particular sanctioning body series, try to make them fit.
I have talked to guys on Corral that "say" they made it work since I was thinking of mini-tubbing my coupe about 4 months ago.