I'd be looking at the springs and bushings first, They get tired over the years. When you say the frame looks good did you have it checked on a frame machine? Thats really the only way too tell if the frame was tweaked.
67 vert 326,2 bl,3 spd,buckets,console,deluxe interior,manual top,3:23,open. Was factory Cameo Ivory but now Mercedes blue.
