My truck dies unless i keep feathering the gas what could be the problem?

Most likely this is a throttle control, MAP sensor, vacuum leak or clogged injectors , either injectors themselves or in the carburator with a slim chance it is a timing issue. Try running Injector cleaner in the fuel first as this is the cheapest solution. Make sure all your plugs are clean and properly gaped. After that it gets expensive since I know of now Throttle controller or MAP sensor test that can done on them individually.