Alternatives to KYB?
The KYBs have a lot of gas pressure which contributes to the harshness. Bilsteins have a lower pressure.
I bought KYBs to put on my 67 Cuda but after feeling how stiff they were and then measuring the gas load I decided to not use them and bought Bilsteins. Besides new shocks I put Firmfeel .94 torsion bars on the front and new 6 leaf springs on the rear.
I'm really happy with how my car rides and handles now, good control in cornering and a firm, but not harsh ride quality.