One other important item I forgot to mention. This pertains to open and locked rear end alike. The rear tire circumferance must be perfect. I mean perfect. Any diviation, even 1/32", will cause a problem at speed. I true my own tires on my car (too long to go on about here) mark them for the same mount spot every time they are off. Same for wheel runout. I use forged wheels when I can because they are perfect. I've beaten every steel wheel straight before I mount tires......Good Luck....JD