I just installed my new drag wheels and tires yesterday.
Stock 70 Challenger, stock wheelwells, and I have no leafs (RMS Street-Lynx). The lower link is right where the front third of the rear leaf would be, but it's only 1.5" wide.

I have Mickey Thompson 3055 (28.0 x 10.5 tires), on 15x10 rims with 6" backspacing. I have 1.5" of clearance from tire to lower link, and about .75" from tire to quarter.

My road tires are Dunlop SP Sport Maxx 275/35R19 on 19x9.5 wheels (I bought that setup before installing the Street-Lynx, I could easily fit 295 tires now.

You may want to tub just the 2 inches between the wheelwell and the framerail, if you want more tire than this.