What is the width of the housing?
It looks close to stock as the space between the housing flange and the shock/lower control arm bracket is about what would be on a stock width rear.
It sounds like you used a 4wd rear disc rear. I am not sure if the actual housing is wider than the 2wd version but he disc certainly is and the actual axles are longer to accommodate the disc. The the caliper is also positioned up higher and the bearing is wider.
I believe you can use just the backing plate from a 2wd blazer to reposition your calipers. everything else should bolt on from the 4wd brakes. to me this would seem to be the simplest solution if it gives you the clearance you need.
http://www.pro-touring.com/threads/9730 ... conversionI know there are spring perch adapters that allow a coil over spring to be used in place of a wider spring. I would look in to that before using coil overs and transferring the vehicle weight to the shock mounts.
viewtopic.php?f=20&t=37550&start=30 Would swapping the caliper brackets side to side help with clearance ( placing the caliper toward front of axle instead of towards back.
4wd drums would likely work too but I don't think you want to hear that
I looked at your photobucket account and it looks like you could pull the tires in further. You could get the 2wd rear discs which position the calipers differently behind or in front of the axle and are shorter. I believe you would have to shorten your axles and change to the narrower axle bearings ( I might be wrong about this).
http://dave.h-body.org/Build%20a%20Bett ... %20End.htm