Is it possible to convert??

Jim Lusk said
The long shackles tend to force Mopar leaf springs to sag past horizontal. This is likely due to the location of the strength on Mopar springs (forward of the axle). This puts a slight "S" curve on the spring.

My daughter-in-law's '65 Mustang has long shackles on it (my son put them on the shortest hole, though). Because Mustang springs are symmetrical they don't sag the same way and tall shackles will tend to raise the back end more.

Ok, this is what I'm not understanding. How is the spring effected differently by the longer shackle. If the back of the spring is still seeing exactly the same amount of weight, then why is it bending it?

I don't have a lot of experience with Mopar rear springs, but in my offroad experience with springs with the center pin offset 6-8" further forward, I haven't had a spring bend like that. Unless it bent due to axle wrap or something binding. These springs sometimes have shackles 6-8" long and shackle flips that can move the rear of the springs 10-12" further down.

I'm not trying to argue with anyone here, I'm just trying to understand why the Mopar spring reacts this way. Maybe there is a leverage force that I can't picture in my head.:banghead: