I'm putting an Air Bar rear suspension w/ a Chassisworks Fab 9 rear end on my 63 Nova SS convertible. I don't want to mini tub it. Anybody have thoughts on the biggest tire / wheel combo I can use? Wheel backspacing? I would like to do 18's on rear and 17's on front but know it will be close. Thanks--I'm new on Lateral G but got to go to their SEMA party w/ some buddies in Vegas