Why? You wouldn't gain much wheel clearance, if any, because the spring would still be pretty much the same distance from the tire at the front of the wheel.
Yes, you could, but it would change the angle of the springs so you would still have to move the perches, or at least angle them to match the springs. You'd have to do the hardest part of the spring offset, ie, moving the perches, and get little to no extra space out of it. If you did nothing to the perches all you would do is side load the rear segment of the springs, probably too much to even get the shackles installed. And even if you angled the perches to match the rear shackles the spring eye wouldn't be parallel to the front spring eye bolt, so, you'd be putting a significant side load on the front bushing. And after all of that you'd probably only gain an 1/8" of clearance to the spring in the front. You'd have more in the back because of the angle, but it would hit in the front so you wouldn't be able to use the extra space created in the back anyway.
