< My next thought is now to stiffen up the rear end with the addition
of a panhard rod (V8-style). Any thoughts on this?>
A panhard rod doesn't 'stiffen' the rear end. It prevents the casing from
moving sideways under cornering loads, often a good idea (I use one on my MGA
race car, as with the stock gas tank there is insufficient room to install
the bellcrank of a Watts link, a superior solution).
I'd suggest that you spend some time with a handling text or two (or the site
several people noted for you, which is excellent). Fitting a 7/8" rear bar,
unless mated with a suitable front bar, is NOT what would be recommended for
I used to use a rear bar on my race car when using an open diff, but not for
close track or slalom use - too much understeer. Out on the track, that is a
plus, and manageable. As my LSD introduces it's own measure of undertseer, I
currently run without a rear bar.