Scott,
The term used is I believe is "shackle". This system of mounting the
spring to the frame has been used for years. You will find old cars,
40's, 50's, 60's have this system. Your problem is not the shackle
but the spring and the shackle. I dare to say the spring has lost its
arch over the many years and needs to be replaced. By increasing the
length of the shackle you are not really fixing the problem. The true
fix is to get new springs made at your local spring shop and put
new shackle and bushings in place. When making the springs you can
ask for different levels of arch. The more arch, the higher the ride.
You can also ask to add an extra leaf. This to will increase the height,
but will make the ride stiffer. Last but not least, you can ask them to
re-arch the spring that is there. This still requires taking them off and
putting them back on. This may say a little money, but I don't think
its a good of job.
This is coming from a man who has had many old cars that have
squat in the rear until new springs are put in place. It is better to
fix the problem, not just put a band-aid on it.
Paul Waddell
WBCCI/VAC/WDCU
66 Overlander
66 Safari
70 Safari
68 Travelall
62 Ford Galaxie
63 Triumph Herald