Well, since nobody seems to follow where I'm going on this topic, let me re-phrase it a bit.
I need to gain about 4 inches of ride height in the rear. I refuse to do it by putting blocks on the perches. Now my only options are; #1 to make the shackles longer and run a double or revolver setup(which I have reservations about doing) or #2 to take a 4inch block and put it in between the shackle mount and frame(which I have never seen or heard good or bad about).
I am leaning toward #2 since it should provide a semi-stock feel, however with proper shackle angles and drop mount design I think it could be extremly flexy.
Any thoughts?