Has anyone had stock coils sag? If so how much are we talking about?

Im trying to get some custom coils made and have baseline measurements, but if my stock coils are sagging then that will toss my measurments out the door.

With stock coils and NO spacer and NO isolator, Im sitting at 39" at the middle of the front fender.

With the 2" spacer and stock coils only, I'm sitting at 41.25"

Im wanting 40ish inches at the middle of the front fender. And yes, Im that picky. I dont want to blow 350 bucks on custom springs and not be happy with it.

My truck has 220K miles. Also when I get the coils springs made I have to add in the extra .25" of the new coil spring isolator.

Thanks for any help and yes this is on other forums, but I want any and all input before I pull the trigger...