1hotdawg
+1y
Are you notched in the rear already? If not, I'd suggest that first before trying to go lower as the axle hitting the frame will be the first problem you run in to. I'm only mono'd with the overload on the bottom still and if I air out my shocks, (air shocks), my axle is within half an inch of hitting the frame.
One option is to put your overload spring on top of your bottom leaf. A number of people have been doing that. I can't speak for if it is as strong as having it below the leaf or not, but it is still probably a safer option than stacking blocks.
Tbh your truck's stance looks about perfect where it is for static. Want it lower throw some 15's wrapped in 50's on it lol.