Slant Six Dead Spot

Check the spark to make sure its a nice strong blue white to rule out a weak coil. Make sure ECU has a very good ground and all ignition wiring connections are clean and tight. Use a non magnetic feeler to ensure the reluctor gap is correct as well though I'm sure if any of this were not good then the problem wold be more of a range of RPM other that just a spot as you mentioned... just checking as I'd be at a loss too I think

Here's pulling at a string... an intake or an exhaust flow resonation at a certain RPM impeeding flow to or from one or more cylinders. ???? as I said pulling at a string