Because they are 40"s and we only put enough air in them to get them mounted. I'm not sure what PSI they are, but they are definitely under inflated in the pictures. It was roughly 1 minute of air per tire and we slapped them on. It was wheeled out for pictures and clearance check, then wheeled back into the garage for more gizmos and do-hickeys.
2.5 BB on 37's ...I'm speechless.
My 33's rub - I guess the Xenon's make all the difference?
The Xenons give the equivalent of 2"+ additional clearance. So, 2.5" suspension with the Xenons gives the same clearance as 4.5"+ by suspension lift alone.
The extended bumpstops that came with my TF 2.5" lift allow people to run 35s with minimal rubbing and stock flares. With the extended front bumpstops from the kit and the Xenons--no rubbing with the 37s.
The 2.5" and 35s pictures above have me on the stock front bumpstops with no rubbing at full flex--showing how much clearance is gained by the Xenons.
I'm thinking that if you are rubbing with 33s, either your kit did not include extended bumpstops, or you are running wheels with more than 4.5" in backspacing.