biggest tire that can fit in minitubbed a-body?

if you get it done and its tight on the inside--the spring side, you can add aluminum wheel spacers , they have 1/4" and 1/2" .

Im sorry---forgot to add that-------- i do have 1/4" spacers on mine. The quarter to tire on the outside is about 1" now. spring to tire is around 3/4" or so