Rear shackle modification

Back before I moved and my car was torn down to nothing, I ordered a set of the Mopar super sport springs that make the car sit up a little in the rear. When I found out I was moving on very short notice, I threw some 4” Jeep shackles I had laying around on it just so I could get the car on the trailer. The factory ones were bent. Now that I’m starting to drive the car, I don’t like the fact that the rear end sits higher than my Ram. Seeing how they’re just flat pieces of metal with holes in them, is there a reason I shouldn’t just drill more holes in them and chop off the excess? How short can I go with them?

Thanks