I believe they are aftermarket adjustable coil overs (possible some home made pieces). Don't see coil overs mentioned in the literature. They did offer heavy duty shocks. The stock shocks were referred to as concentric. Which meant tube in tube. If it's half ton. I would replace with FLAPS shocks shown for that year.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn