Kzinge1 - You'll be less likely to have a a hieght adjustment issue if you talk with Just Suspension and Firm Feel (and any other vender you wish) about hex clocking before you purchase. I know Firmfeel has worked out clocking for stock weight vehicles. Just Suspension I don't know so ask.

Even better, before calling, crawl under or drive up on some 2x10 boards and measure the Chrysler ride hieght. At the same time, note how far in the torsion bar adjuster bolt is. Stock ride height is availble from any shop manual. The 1970 Chiltons's says 1968-70 Plymouth [Belvidere] spec is 1 3/8". Now you'll have some points of reference when talk to the vendors.