It would probably be best to replace the early spring hangers with hangers from a 76-86 CJ 4wd hardware sells them for around $15-16. In addition to the spring getting wider, the spring hanger bushing also got bigger in diameter. I looked at my '72 and I think you'd have a hard time getting the later springs into those hangers. Even if you stretched them that would only solve half the problem. I think the bushing eye would rub against the frame and stretching the hanger would move the bolt hole closer to the frame. BTW, National Tire and Wheel is selling Superlift 4" kits for early CJ's for $379 with shocks and hardware. I just bought one 2 days ago, so I assume that price is still good. Are you really dedicated to the D-C kit or are you just having a hard time finding a kit for early CJ's in your area? My total for the 4" kit, extended brake lines, and shipping from WV to CA was $550.
My other car is a BULLDOZER
My other car is a BULLDOZER