Just got this in the mail today

Re the distributor connector. Lookup my post where I found different types of that "double bullet" connector. Some have a shorter male terminal that doesn't make a good connection, which is likely the source of intermittent problems.

I prefer the nylon gear since it won't wear out the camshaft. Slant camshafts are not common and changing a cam isn't trivial. You can still get replacement gears cheap, so keep a few spares. Best backup is a points distributor in the trunk.

Did the Mancini kit come with a wire harness, or at least the connectors? Price? I changed my 64 slant to electronic, paying $40 for a new e-distributor (ebay), $7 for a pickup (rockauto), and ~$15 for 8-pin HEI module, coil, and cables (PickN'Pull). If I was you, I would consider selling the orange box & ballast and wiring an HEI module and E-core coil. It is a lot of work to wire the inferior and problematic Mopar module.

While you have the distributor out, check the vacuum advance. I think the one with the bent arm, labeled "8.5R" gives better mileage. At least I ordered one termed "high mileage" on rockauto and that is what I got. It was cheap.