TTi dual exhaust '67 dodge dart

Yep, they're tight. You might be able to get a bit more room by loosening up the tank strap and forcing the tank over a bit more, and tightening it back up. Don't expect miracles, though. I've seen 3' in there- and I don't think there's anybody on the planet who moves the leaf springs OUT, exhaust diameter be damned. If anything, they're moving them in to gain tire clearance- I have heard of (and seen) tanks get narrowed in order to gain some clearance in there, though.