Hi,
1st off you or me could never drive our cobra's on the street fast enough to warrant an independant rear end. choice is another matter.
2nd if you want to track the car, you do what you want to do; drags are only for a built 9" Ford, NHRA doesn't allow IRS in faster cars. Road racing is IRS, but then you better have a full roll cage and fuel safe cell or your toast.
3rd, a show car has just too much money thrown at it and do whatever turns your crank.
HAVE FUN with your COBRA.
Perry.
