Ok, time to tell a story with pictures!
Just for reference I am starting with 03-04 SVT rims, 17x9 with 26mm offset.
I will be running 275/40 tires all the way around.
I have 1.25" spacers or about 32mm. So the rims are at -6 offset. I had rubbing with 16x8 rims at -11 offset and 245/50s.
Ok, here's a pic showing clearance to spring. Plenty, good!
Here's clearance to wheel lip (on the side that rubbed) Not bad, but should be better. I could remove the moulding and roll the lip as is it seems, but with all the clearance behind the rim, shorter spacers look to be the best decision for the rear.
Just a pic to show overall appearance in the back, not bad. Yes, I should blast and paint the drum, or get rear discs... maybe sometime before Carlisle.
Overall front view. Tire is a 245/50. Car is on the ground, so its a loaded suspension. That a 1" larger diameter than a 245/45 (so take a 1/2" off the radius, 275/40 has the same diameter as 245/45)
a decent look at the fenderlip clearance. Again out too far.
Ooops, hits the fender. Plenty of clearance when turning the other way, including frame rail.
So the next steps is to mount a 275/40 tire and purchase 1" spacers. (a pair to start) Test fit from there... I have a feeling the wheel well molding isn't going to survive and I may need to slightly trim the front fenders...