275's on a dart sport

I made 325s on 10s fit by pounding the living daylights out of the inner tubs where-ever they rubbed, during cornering.When they finally rubbed equally everywhere, I spaced them out an extra 1/8th and called it done. Then I lowered the car till it rubbed on those aforementioned bumps on the outer skins. Then I started pounding those. But I quickly learned, that you can't really pound those without it telegraphing it to the painted qtr skin. So I jacked it back up an inch, and installed some HD shocks. Shazzam !,it was done. I can drive pretty hard now, cuz when they rub it is always on the inner, and I have pounded that smooth. But I can't put big power on in the turns.It's ok for the street.Well after making those 325s fit, 295s on 10s, just fell in there.
To answer your question, IDK the measurement.
Wait, I found some old notes, from Dec 98; it looks like 13.25, from the inner to the backside of the painted quarter,Not the lip, but below the offending bulge. I folded the lip up as tight as I could to the back of the qtr.