Points Gap on chevy distributor

[PeteVS]

That Chevy distributor has the possibility to set the dwell with the engine running. That is if you have a dwell meter. Set the dwell and THEN set the timing
I have a couple of those distributors and I've found that if you leave them for any appreciable time, the contacts oxidize and I get no spark. I've converted a couple to transistorized. Seems that the off shore repros are no where near what the OEMs were.