You have replaced the parkneutral switch starter batt cables distributor module and engine wiring harness for your Chevy 350 and you still can only get your truck to start sometimes Any ideas?

A shotgun approach to automobile repair is guaranteed to maximize your expense and minimize the probability of actually repairing the problem. Unfortunately, there are many repair shops that use such a method, with the preferred mode of operation being, "just keep repairing parts until it runs. If that last part didn't make it run, it doesn't matter. We'll tell the customer it needed to be replaced." Use logic and empirical method to solve the problem: What is it doing/not doing? Create a hypothesis: "Is it the _____? Bypass or directly test the suspected component. For an intermittent problem you may need to repeatedly test the component to see if you can cause it to fail. For example, if the starter engages intermittently you may need to run a direct wire to the starter solenoid and use the direct wire to bypass the neutral indicator, keyswitch and original wiring to see if the starter will function reliably when you use the bypass wire.