Try it without the rear bar and see how it goes, or find a larger bar for the front. On the Vega, I had a 1/16" front bar and a 3/4" rear, stock springs, and a set of PST bushings. I was running a cheap set of hydraulic front shocks, and a set of KYB HP gas on the rear. Before anyone rolls their eyes, I had also run Mulholland, Konis, Gabriel Striders, and the KYB's on all 4 corners. For what ever reason, the cheapies/KYB's worked great with the stock springs. If anything, I had a touch of understeer with that setup, but not enough to "grind" the tires in a tight corner. What type and size tires are you running?