Super Stock leaf springs

That spring is never going to work, that shackle is too far from ever being vertical that you are correct, it will try to pop back against the body if it gets a chance. When the car is lifted and suspension is in droop the shackle should do no more than align with the spring. Did you buy those SS springs from Mancini Racing? I practically threw one spring out it was so crappily made. Either way I went to ESPO for springs, no issues.

Also, leaf spring suspension is the easiest to set up and to get it wrong it is a parts issue, not a person issue. I had a trailer that I made that I got the shackle angle wrong on due to setting it up for typical 25.25“ trailer springs and guess what, had 26” springs… so every chance the trailer got the shackle collapsed against the frame. Replaced the springs on it with 25.25” springs to get the shackle vertical and never did the shackle collapse against the frame again. And yes I saw it before it happened and said “It looks weird but it is supposed to look like that, it’s fine.” It was not fine.

Additionally, I always understood that using shocks to limit suspension travel was a big no no because it would cause the shock to beat itself up at the end of travel, and ultimately fail. Shock is designed to dampen the shock loads anywhere in the suspension travel and have more range of travel than the suspension it is dampening.