Hotchkis leaf springs sagg brand-new

Thanks everyone for the quick responses...i know the shackles arent stock, what i should have probably said was 'stock length'. Ive shown hotchkis the same images, they did not suggest to change rear shackles or the front mounts out. I will be replacing them though, i did not see them as that big of an issue before.

I understand when working with 40 year old cars unexpected things come up...And yes jos51700, i wish i had bought some MP springs (what i had run before) and de arched them, but now i dont want to be out more money trying to fix the issues that an already expensive kit has; i feel that theres a reason their kit costs double what other leaf springs cost, usually thats quality, but hopefully its also support (like ive heard)...Ill see what Hotchkis has to say and will know what im doing by mid-week.

EDIT: This interests me from your link abodyjoe, a quote from GMachineDartGT:

"I measured the arc of these springs against the factory 340 arc measurements and they aren't far off. Since they sag so much, I am led to believe they are way less in rate than the 130lb they advertise. Factory 340 leafs are 110 lbs. In fact, I just replaced the Hotchkiss springs with 102 lbs springs that have a stiffer feel without the height issue I had with the Hotchkiss pieces.

For the record, I did call Hotchkiss and ask for designed install heights, and they had none."

In all the measurements i took for hotchkis in this process, they were correct length, eye position, etc...
I had mentioned to Hotchkis that my rusty, 40yr old stock slant six leaf springs held the car up better than their springs. Sure i could change the front mounts back to stock, and the rear shackles arent stock and may be causing some slight issues, but to me those changes are band-aids to the real issue- everything still points back to the springs themselves. I can lift the rear end up by hand at the bumper, ~150-200lbs of force will move the shackles off the subframe.