additional drop

[gGMC DOG]

i have an 81 gmc that has 2.5 drop spindles on the front, with the stock coils cut for an additional 2" drop, flip kit out back, running 27" tall tires in the front, 29" in the back. what i want to do is put bags on the front so i can lower it down a little further when parked and raise it up when driving. going to do this a little at a time, bags on the front first, then the rear. my question is, how much additional drop on the front will i get when i put the bags on, if this can be answered.