Rather than grind away material - get some 1/2" wide flat bar that is the right thickness to make the height the same and cut 1" long sections. Put under the low side of the bridge... If need be tack weld them with a MIG to hold them to the bridges while you put them in place. Should be a lot less work than removing material and you don't mess up the bridges.
51 GMC 4.2 turbo Can't solved today's problems using the same technology/thinking that created them
