I have used Caps Automotive Products & Reilly Motor Sports SUSPENSION stuff, adjustable upper & lower tubular control, arms both with great success, either will make night & day difference in the handling over the stock type suspension, add a rear sway bar, a larger front sway bar, larger diameter torsion bars, o/s or adjustable strut rods & quality gas shocks will also improve the car leaps & bounds.... IMHO The tubular K-Frames are much lighter & have much more room, for steering, headers & oil pans, but are very pricey for very little return/improvement on the money spent... I'm currently going to install some Caps products listed on my 68 RR this spring, I have had great success with them & the price is not bad at all compared to other brands & they are a Mopar only specific brand... Good luck, even just poly bushings, gas shocks & sway bars will make a big difference....