My 78 Lemans with 95000mi had the same issue, i tightened up the steering gear and it helped a little but not alot, new idler arm, again a small improvement, then i put in camaro front coils, new upper and lower ball joints and drop spindles. Now with the exception of badly rutted pavement mine tracks straight. I also did the camaro quick ratio box and camaro rear coils, the rear helped eliminate the sloppy side to side movement back there and i havent even put my rear sway bar in yet.
My coils were very soft and i did have a lower ball joint that seemed pretty sloppy once it was apart but i couldnt tell when i checked with everything together.
My coils were very soft and i did have a lower ball joint that seemed pretty sloppy once it was apart but i couldnt tell when i checked with everything together.