To remove rivets, the best way I've found is with air tools--at the least, a cut-off wheel. Cut an line across the head of the rivet, and then chisel the head off in two pieces. If you have easy access to the rivet head, cut an X across the head. Go deep, all the way through the head. You can chisel off the head with a cold chisel and hammer, though my knuckles prefer using an air hammer.
Then a tappered drift to bang the rivet body out. Again, I've also got one of those for my air hammer (bought a Craftsman set of air hammer attachements several years ago).
I replaced the spring perches on my '97 Dakota with lowering perches, and drove it for about 30,000 miles before it was stolen. Did the same on my 2001, and I've drive that one for 160,000 miles, and the grade 8 bolts are doing just fine. I check them every now and then, but have never had to tighten them, and they aren't loose in the hole. These are on the bracket that is holding the leaf spring to the frame.
-Brad
