Upgrading to electronic ignition help

71duster06 said
Has anyone had any experience or knowledge of any performance change when switching from an oem style/mopar distributor to the firecore?

Also yes this is going on a 340.

Of course there is a performance change, and there always is when switching from a standard ignition to an HEI system no matter who makes it.
As far a the firecore quality and reliability I have no personal experience.