I have a 350 mild motor that has developed an engine misfire over about 3,000 RPM. I have replaced most everything on this car from carb to wires, plugs, fuel filter and cap and rotor with no improvement. It is a MSD HEI unit and looks pretty new but my question is could the module or the coil cause a misfire at higher RPM? As long as you drive it under 3k it runs and drive fine. No speed shops use distributor machines anymore so it is hard to have this checked out without just starting to replace parts on it.

 

What spark plug gap are you running?

 

You could have a faulty rpm "pill", do you have an extra one to test with?
I have the adjustable rpm module, mine isn't on the pill.