The original lower shock mounts on my 59 appear to be bolted to the bottom of the axle housing by the leaf spring U-bolts.
This puts them at an angle up to the upper mounts, which are riveted inboard of the springs on a crossmember.
I am not sure the original lower mounts would work with a late-model rear as they have 3" diameter and I think (but don't know for sure) the original rears were not this large. But they could possibly be modified for re-use.
You can somewhat see what I am talking about in this photo:
http://rides.webshots.com/photo/2556910870100598759xZZgoL?vhost=rides Note that only the right side shock is still attached in this photo.
I currently have my stock lower shock mounts still attached to my truck frame/rear diff if you would like some better pictures.
In my limited experience, when I add a more modern 9" F*rd rear-end, I am going to change the shock mounts so that the shocks are more vertical with the travel of the axle, and fabricate the mounts so that one shock is ahead of the axle and one is behind. This arrangement prevents wheel hop in the Hotchkiss-design live rear axle mounting.
Yes, moving them further out would be preferred to close to the pumpkin.
There are some books out there that address this. You could start with "Chassis Engineering by Herb Adams", and "How to Build Hot Rod Chassis by Tex Smith". Go to Amazon books and search on "chassis". Hope this helps.
