I am in the process of going from conventional points/condenser to electronic spark. A unit that is not seen from the outside, looks original. My concern is what should be done to the distributor to prepare for it. What should be replaced or checked for wear?  What unit is acceptable for a car like mine? What about plug wires? Will my NEW 7mm GM wires work?   THANKS   Engine is being rebuilt and will have a small up grade in cam and HP.

There are a few upgrades that go inside your existing distributor and use the same cap and wires.  Any of them will be fine.  While you have it out, check the distributor main shaft and bushings, cross shaft and housing, mechanical advance mechanism, and check vacuum advance for leaks.If you need to replace the main shaft bushings, you need a special hone to resize them.  The rest you can do yourself.

Larry