for Pro-Stock
early 70's...state of the art was ladder bars and leaf springs.
for a short period (71-72) there was the leaf-link. leaf spring on the bottom (to locate and hold the car up) with 4-bar link on the top.
by 74....it was all 4-links
that's how I remember it.
View attachment 1716136692.
the suspension pictured is the 1975 Direct Connection Duster Butch Leal raced in NHRA modified production (M/P). The rules required OEM front and rear suspension (leaf springs) and allowed traction / ladder bars.