Sounds like this is much like my 350 SDL ... is there a spring and a shock that form the basis for absorbing the tension?
Mine was a bit tight, but no big deal after you unbolted everything. I understand the problem (on the diesels at least) is that the bushings get beat up ... they supposedly fixed this on the replacement shock I got. About an hour - I am slloooowww the first time.
Don't forget to replace the belt when you do the shock replacement ... perfect time. Cheap insurance. Keep the one you take off for a spare!