There is little to gain by doing it.....and if you look at a Goose chassis you will be drilling FAR more than "just the shock mounts"......You really are talking a LOT of work to do this. Look at the front upper frame mounts if you don't believe me! In fact, I don't even know if you could drill out the front holes!!! Not sure a typical hand drill would fit in the trunk area to even make it possible.....then it would need to reach about 5-6" to boot! (That's how long the upper shock bolts are....front and rear!)
Out back would be possible, but would require drilling out the holes in the ladder bar, which are bushed........but just easier to stay with stock 10mm bolts!!!!! Unless you have a late car...
I would advise that before anyone starts cutting any metal to make the adapter bushings, that there is only one dimension that I trust on the drawing, and that is the diameter of the hole that the bushings fit into! .500"...... everything else should be confirmed for fit to your chassis! ie stock 33mm width........
If I come across my notes for the adapters I had cut up.....I will be certain to post!!!
Grazi!
Steve