my new 12 bolt (77 suburban 1/2ton axle) is back 2-1/2''
I used the 1-1/2'' kit from chevy duty
http://www.classicparts.com/prodinfo.asp?number=93-311 and still added a 7''x1-1/2''x1/4'' plate welded to the bottom of that 3'' U axle part of the kit. That 3'' U axle kit part has a hole for the re~centering the pin of the springs back @ 1-1/2''. I drilled a hole in the new 1/4'' plate to locate the spring pin back 1 more inch then welded the new plate to the U axle part. this was needed to clear my under bed gas tank to fit in front of the axle and high up into the frame. I used my old stock gas tank filler neck (rotated 180 degrees) to now fill the new under bed tank.
but
It sits beautifully and is a well centered tire.
i had to get a new drive shaft anyway so what the heck.
http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=009535;p=1#000003
