Dart dies when hot???

yeah, that 140019 looks to be a matching HD E-core coil for CDI, and continuous use.
Is yours still wearing it's extruded aluminum heat sink?
Make sure your wiring will support the amp-draw of that system; I recommend a relay so you don't pull that all thru the ignition switch and more importantly;not thru the bulkhead connector.
Oh wait, I think that -6box has a built-in relay and the power module is wired straight to the battery, sorry.