Hi,
I’m not sure if this would help or not
When my TC was still under warranty I was trying to get it levelled out by offsetting spring rates according to chart to correct leaning left conditions
Many times the front end guys would add shims in the left side K frame to body connection to get it levelled out. Certain mustangs and tbirds had a left lean right out of the plant.
I used to have a TSB from years ago that had service springs for mustang / thunderbirds. I put it somewhere for safe keeping which I should stop doing because It’s so safe I can’t find it.
These are 2 different I tried for the rear the. “M” code was for the left
Sorry the tags in the pictures can be a bit tough to read
Service part # E7SZ 5560 M
Engineering #. E7SC 5560 MA
Spring rate 35.0/4466
Service part # E7SZ 5560 K
Engineering # E7SC 5560 KA
Spring rate. 35.0/4086
I later ended up changing to this set of TRW springs which are still in it today
Also changed the left front spring as well to a higher rate per chart
