1993 chevy 1500 4.3 steering wobble (BAD)

[Bob252]

Front end wobbles so bad it feels like the front tire is oval instead of round. Between 0 and 45 mph the steering wheel moves side to side so bad that i have to slow down and jerk the steering wheel to get it to calm down. At 55 to 60 mph i can still feel it but it is drivable. When braking: the front end shakes back and forth. To minimize this I pump the brakes. Does anyone know the main cause of this?. The body of the truck has 390,000. I know I have bad ball joints and other worn parts. But I don't have a ton of money to spend on it. Please help.