Already have the MSD 2900 kit and I will be converting a customers 1968 Corvette. Already have the kit along with a new Edelbrock airgap intake manifold. Still have to source a fuel pressure regulator because they recommended it. The car already has a converted OEM distributor with a Petronix system. What is needed to have the Atomic EFI control ignition timing. The car has a tachdrive on the distributor and the only thing MSD has is the #8572. Is it necessary to use this distributor along with an MSD 6AL box. If I wanted to convert the tach to electronic would there be a better distributor to purchase to simplify the install without the ignition box. The engine is stock with a mild camshaft.