[Gunner]

The issues with a solid rear axle in something Mustang-sized are quite different from those in a Cobra. A lot of the problem with a live axle in a Cobra is the very short wheelbase- with only 90 inches to work with, the distance from the tailhousing of the tranny and the nose of the differential is a foot or less. That doesn't permit much movement of the differential relative to the chassis, limiting the overall travel of the rear end. Little travel, little compliance, big magnification of hop and chatter and stiff spring issues.

My Mustang has a driveshaft some four feet long - meaning rear end travel can be substantial, and is, and that goes a long ways towards ameliorating the problems.

There are places to save money on a Cobra. Using a solid rear axle is not, IMVHO, a good place to do so.