What is the size of the stock rear sway bar?
Original Post
The stock front & rear bars were about .780, painted black (dunno the metric size). The Euro GTS with 10" rear wheels got an approx. .875 dia rear bar. IMHO, this is the best handling aid you can hang on your Pantera regardless of the tire size. Understeer or plowing at low speeds is reduced significantly. But more ain't always better: in a skid-pad test many years ago, going from a 7/8" to a 1" bar REDUCED cornering power, probably from rear subframe flex. And I don't recommend the hollow sway bars currently on the market. They usually break due to stresses from tack-welding the guide washers to the bars with no heat-treat after welding. If you find some washerless hollow bars, the ideal size would be about 1" since hollow bars are a little less effective for a given dia. but a LOT lighter than solid bars!