Race car suspension?

Ive got a 71 duster w a 360 with some work that I am going to be bracket racing. Yesterday I took it out on a back road by my house to try it out being that I just installed the engine saturday. I know I need to do the brakes cause when I hit the brakes it trys to turn right. The brakes also havent been gone through in the last 10 years. But my question is what can I do to the suspension. At high speeds I REALLY have to drive the car and cant keep it straight. The front suspension is all factory except a new manual gear box. What are yall doing to get a pretty good solid suspension with out breaking the wallet.