72 mach 1 rear suspension issues

So my 72 mach 1 sits really low in the back. By that I mean like the edge of the tire is hidden by the wheel well. The springs are new and the previous owner thinks the shackles need to be straightened and tightened. They are pitched a little as opposed to being perpendicular to the ground. Im wondering if i need new shocks and the shackle straightening and that will fix the issue. My pic shows the car as it sits.

Thanks,

James  

I think that it would also benefit to check the leaf-springs. But new shocks never hurt the ride quality of a car. If the shackles are not quite right that should definetly be a priority because if they are not straight it can be causing binding when the suspension compresses and/or rebounds. Hope it helpes and works out for you.  JC  

I own a 1973 mustang shown in readers rides. The problem usually is the selection of the rear springs. A good leaf spring shop can re-arch the spring to the correct ride height. If the springs are selected wrong the car will sag in the rear. Some owners will lower their ride by adding a block under spring perch which will lower car but mess up the pinion angle. I use to have an extra leaf on my race car but it is gone now. Do not add longer shackles then stock as this will add other problems.

Good Luck
Steve  

I have a 71 and I have the same problem.  NPD used to sell a high-lift leaf spring that I bought and it helped a little.  But I still feel like it sits too low.  I was getting ready to try the 1" longer shackle kit.  The previous post said it will add other problems-what problems specifically would it cause?  

The shackle must be heavy duty (thicker)and the bushings will have more side to side torque on them, which must be compensated with poly type bushings which may squeak. I mentioned  extra leaf will also fix the problem (it is put between the main leaf and the next leaf).