HEI IGNITIONS

A stock HEI is not a good choice for a racing ignition due to the fact that the stock Ignition Module does not conduct long enough to allow sufficient (dwell) time for the coil to recharge.  This is evident in the upper RPM ranges say above 4000 rpms. It will show up as a intermittent miss or the engine will act like it's running out of fuel. 

You can have a case where a stock ignition will  be enough to support a Two Barrel carburetor in the sense that it will not miss and cut up in the upper RPM ranges on the track. But if you were to witness this same engine running on a Dyno there  would be a horsepower loss. 

The same engine with a Four barrel, even if it didn't miss could show an even greater loss in Horsepower. I highly suggest running an MSD ignition I am not saying that others are not as good or better but we have had very good success with MSD products.

Trouble shooting hint:

A faulty ignition module can exhibit the same symptoms that a fuel delivery problem would .This can show up even in off idle conditions and at moderate engine speed.

Jimbo