I finally decided on a sway bar configuration for the project. I found a couple of sway bars that would fit (Porsche 911 rear bar was one that would fit almost perfectly), but not knowing exactly what I needed in terms of size, I'm not ready to use them. Because of limited sizes from donor-car bars, and not wanting to commit to custom bent bars (unless I knew exactly what I needed), I decided on a NASCAR style bar. They are cheap on Ebay, come in a multitude of sizes, and can provide an almost infinite range of stiffness with the long arms. I chose a medium-sized diameter of splines (1.25") (because of the long list of available diameters), and am using the standard 37.5" length. I was able to purchase a group of the smallest 4 bars on Ebay for real cheap (new), so the only thing left to do was install them. Again, my chassis does not lend well to the addition of yet another piece of equipment in an already very cramped space under the bodywork.
These bars can use a tubular housing, which I chose to insert in place of the existing rear bulkhead crossbar over the transaxle. Thus the bar's housing in essence is a part of the framing. I removed the existing brace, modified the posts that hold the cross-bar, and then machined and welded all the aluminum parts needed to bolt the sway bar housing back in place.
Existing cross-bar:
After the top of both posts was cut off, I inserted a machined piece of aluminum into the ends (drill press and carbide tipped hole saws make a poor man's milling machine):
Drill and tap threads to fix plates into each post:
Then weld saddles (2" square tubing) onto the top of each plate that will hold the bar's housing in place. I welded a long piece in place, and then cut the ends off after it was all done to ensure they were aligned with each other:
The housing in place, but not yet welded to the saddles. Plastic bushings slide into each end, and then the sway bar slides into the bushings, with shaft collars on each side to hold the bar and bushings in place:
With bar installed: