Re: Cortina Susspension
I have a TC Cortina and I too have experienced the right side sitting lower than the left. The first and easiest trick to try is an effort to determine if the problem is merely spring sag. Over time springs can lose some of their tensile strength, so try swapping the the left and right rear springs over. Its not a permanent solution I know, but it will let you know whether or not its the second problem.
Since thr Cortina is a Pommy designed crap box, it was only ever meant to have an asthmatic 4 cyl in it (they even had 1.2Lt carby fours). That was until the top blokes at Ford Australia dropped a dirty big 6 in it. They can usually handle a 6 in normal conditions, but work it or give the car a hard time and the chassis can twist. This is what has happened to my car (mine has a 351W in it).
If I swap my springs over it sits level, then if I go for a drive it sits crooked again. Not much you can do short of putting a worked Honda engine in it and flogging the ass off it (they rotate the opposite dirrection, would need a new 'box and diff too unless you want to go really really fast in reverse. lol.)
Hope this helps.