Chevy 350 help..

The pick up for the distributor either works, or it don't. Its not the problem. I think those engines have the spider injector rail inside the intake. Some times one of the injectors will clogg. If you have to change that, its a ***** to do usually. Try some fuel added injector cleaner and see what happens.

The spider injector system is on the Vortec engines, used after '95. The one in the OP's Blazer is a Throttle Body Injection system.