Regarding coil-overs, John Sandbergs SCCA C/Prepared AAR eventually ousted the TBs (1.24) and he went to yet stiffer rate coil overs (becuase the 1.24 TBs weren't stiff enough... and had he considered swapping hexes he would have done that but concentrated on the entirely new setup instead).. and the class rules permitted the swap.... he did the same in the rear (ousting the metal xxhd leafs)... he completely re-designed the suspension front and rear (professionally engineered).. result: eventual higher class finishes/more wins and the SCCA national championship C/PL crown. There's a place for coil overs when the TBs aren't stiff enough. Suspension travel remains acceptable for the intended roads/courses driven (always following club rules!, etc). His previous TB/leaf complete overall setup, etc, now resides in his son's 73 440-6 Challenger (also has full fiberglass front end)... street/hwy driven, occasional road course lapping sessions.. an awesome car!

You can read about John's SCCA C/P AAR in Mopar Action issue August 2006 along with my T/A for most of the details. (John's AAR was also featured in Mopar Collector's Guide about 1-1/2 years ago.)

John did install splined sway bars front/rear.... many variable choices in that segment.