keep in mind that while these will give you adjustable shocks and spring preload, they will not improve the motion ratio or suspension geometry. These are things that are usually addressed with the pricier conversions.
also, with dampers, you usually get what you pay for. meaning more expensive shocks generally work better and last longer than cheaper ones.
that said, i have no experience with CPP suspension, so cannot comment on the quality of the parts or the tuning of the spring rates or damping.
65 GT Vert 4sp