Hello & happy dry Monday. No rain yet... I'm hunting references for a new drop-in replacement distributor for a stock '57 392 C motor / generator. I was hoping to find an electronic unit - with vacuum advance. (is the vac. advance necessary when going breakerless?) The unit I have has a bit of shaft play and a non-functioning vacuum advance... So far I've only found units without the vac. advance. What's best? Many thanks & have a nice week.