Chevy 350 help..

The pick up for the distributor either works, or it don't. Its not the problem. .

Sorry, this ain't true

It might be rare, but dist. triggers do develop problems, sometimes due to dist wear, strike damage, or magnetic debri, AKA rust or filings

We even had at least one guy on this board with a Mopar ECU that was triggering erratically, something I did not think would happen.

I would concentrate on one or two cylinders being a problem

Bad plug wire, even a plug, low compression, head gasket.

Run a cylinder balance test by grounding each cylinder. NOTE I said GROUND, do not remove plug wires and let them fire open.

Run a compression / leakdown test