Spring Relocation Question

I'm building my own spring relocation kit. My question is: if I mount the front spring boxes flush with the outside frame rails that leaves about 3/4" offset to the inside. Do I weld the rear tube 3/4" offset to the inside as well? All the pics I've seen the tube is centered in the frame. Seems logical to off set it as well to keep from any binding. Am I correct in thinking this? Also, if I move the front spring hole to the rear 1" (to gain tire size) and use the existing hole in the frame for the rear spring, this effectively reduces the length of the spring mounting by 2". Will this cause problems?
Thanks