ignition system ?????

A stock GM HEI module when mated to a stock style coil actually has less rpm potential than the stock mopar ecu with the stock style coil. The scope traces I have seen show the HEI breaking down around 5200 rpm verse 5800 rpm for the mopar.

You need to use a HEI type coil and/or an after market module to see any real advantage. But then again the mopar performance chrome ecu or the FBO ecu from 4secondsflat.com can produce a reliable spark up to 8000 rpm.