I'm running TTI 2-1/4's on my B Body, we had to modify the pipes for clearance, especially at the steering gear & torsion bars.
Can't complain about the quality and finish but nearly everyone has encountered fitment issues with larger pipes. I believe it is just the way it is, they're BIG pipes and, as you will no doubt know, a Hemi has poofteenth of zero space in terms of available room.