Maximum tire width with mini-tub

I saw that a guy recently fit some 265/40/R17 in his 1965 barracuda with the springs moved inboard and the rear moved back 3/4" in a totally stock wheel well. This is pretty impressive for an early A. I however am curious about the maximum wheel/tire width combo that would fit in a mini tubbed 65 dodge dart. If anyone has ANY experience with mini tubbing and early a's I'd be glad to hear it.

Thanks!
I have Mickey Thompson N-50X15's on my '65 Dart. 14" section width. Springs are set into the longitudinals and the inner fenders were actually made from Chevy pickup inners as the originals were so rotted out.