Here are the front mounting holes for the LH leaf spring in my frame; note where the Silentbloc bushing has gotten loose, and worn into the inside of the bracket.


The first thing I did was to get some 7/16" nuts, and drill them out on the drill press, so they would slide down the shank of a bolt. Then I assembled them in place with just a plain 7/16 bolt, and tack welded each of the drilled nuts in place in a couple of spots, to preserve the hole locations. After removing the bolt, weld bead was added to the holes on the opposite side of the bracket from the nuts.


And then the nuts were used as a guide to drill the holes back to 7/16" diameter. After drilling, the tacks were broken to remove the nuts, and both sides of each hole was ground smooth. The above picture shows one of the bolts supplied by Todd Clarke. This is a very high grade bolt, maybe even a little better than grade 8 (head is marked 160ksi), and plated silver zinc to match the original.

The wear seen here was obviously due to loosness of the bolt, allowing the center tube of the Silentbloc bushing (and the bolt) to move around with suspension motion. When properly tightened, the inner sleeve of the Silentbloc bushing would be firmly clamped inside the brackets so the bushing tube and bolt cannot move. The bolts should be tightened once the full weight of the car is on its wheels so that the bushing is centralized.