It actually doesn't depend on what kit you use. While the MP kit claims to move the springs 3/4", if you actually measure the front hanger the difference is only 1/2" from stock.
I have a MP set on my Duster, and I measured it and compared it to the stock hanger when I read Dr. Diff's comment that the MP kit only had a 1/2" offset, just like his. There's only a 1/2" to the frame to move the front hanger. And because of the recessed bolts Dr. Diff uses, you don't have to cut a hole in the frame like you do to clear the front eye bolt like you do for the MP kit. I wish I'd known THAT before I installed the MP kit in my car.
You can put the perches in 3/4", and it will get you a little extra space, but it also puts a side load on the springs. I installed my MP kit with the perches at 42" C-C, so the springs are in line with no side loading.
I understand the offset rear shackels and moving the spring perch,, but with that set up do you just leave the front spring mount in its stock location?