All new suspension... why is the ride so bouncy?

[Reyals Bemus]

I've replaced every single wearable component in my '64 C10 panel truck's front suspension with top quality Moog or Raybestos parts. The front end has been lowered with drop spindles and 1.5" lowering springs. The rear has 4" lowering springs. An ECE 1 1/4" sway bar has also been installed up front.

I've gone through three different sets of shocks trying to find good ride quality, but I just don't feel like its there. The front shock control is the main problem. First I had KYB Excels (also knows as GR-2s). Those were totally lame. Endless bounce over every bump. So I stepped up to KYB Gas-a-justs. Those were better, but still didn't control the bounce as well as they should. By bounce, I mean the truck's tendency to continue bobbing up and down after hitting a bump. So finally I shifted gears and sprung (haha) for Bilstein 4600s hoping that their superb reputation meant a superbly designed shock. To my dismay, I could not feel a single difference between the Bilsteins and the Gas-a-justs! It just feels like all these shocks are under-dampened, especially on rebound control.

What am I missing here? Am I asking too much of this old truck? I own other 60s era vehicles that all ride better than my panel. Can anyone make recommendations?