Russ, height is right around 23 3/4" front and 24 3/8" back. The fronts have never rubbed, ever. Back is where things are tight. Had to slightly trim inside of wheel well for clearance, as it would rub going over bumps. Since then, only had slight rub one time; there is a big dip in the road and I always fly right over it without even thinking in 2009 Challenger but need to slow down a bit for that spot with 1970. Just guessing, but think if you wanted to drive aggressive autocross, then a smaller tire in back would work better. You are going to have to drive fairly hard to get any significant body roll with the TVS, but once you generate significant body roll, that might cause clearance problems with the 255s on back.
Hotchkis customer support and the owner of the Challenger in the Hotchkis video were kind enough to field my questions when I was sizing wheels & tires. The car in the video has a 440 and is running 235/60/15s all the way around. So you know with certainty the 235s will work even when pushing your car for all it is worth in the corners...
P.S. Russ & Brads70, thanks for your kind words