Re: rough ride
If you have the original monos and they are tired, that may be the problem. Springs just lose their spring after a while, and 37 years is certainly a while. My 68 had the original multis re-arched by the previous owner, which helped ride height, but they were so worn they weren't really functioning as designed any more.
I think the general consensus is that monos ride better than multis. Monos are just very limited at controlling axle wrap when there's some HP to put to the ground, so a lot of folks go to multis.
Many of the guys on here use the 3-leaf Nova replacement springs that JC Whitney sells, and like them a lot. They fit pretty decent in a monoleaf perch. If you don't have a lot of HP, you may just want to go with replacement monos.
I think many here like the Monroe Sensatrac shock as a reasonably priced choice, but I don't think they make a Sensatrac for monoleaf applications. I'm running KYB Gas-A-Justs, but some folks think they are too stiff (I have a big block to keep planted on both ends, so they are okay for me). The KYB Gr 2 shocks are supposedly pretty decent too.
What type and profile of tires are you running? Low profile tires with stiff sidewalls don't help ride quality.
Also, how are your bushings in the rear suspension and under the front subframe? If these are worn, they can make it harsh too.
69 'vert project big block/TKO 600 RR
68 'vert driver RS clone -- gone!