Msd pro billet in a small block 360 backfire at idle

Score! There is a saying: "when all else fails, RTFM"
:thumbsup:

EDIT>> did all Pertronix models use that little plastic reluctor overlay? I though the old ones triggered off the original points lobes. Always thought that was a crazy way to trigger an electronic distributor as the lobes are 'soft' when it comes to tripping a hall effect or magnetic sensor. Pointy finger reluctors ie. Mopar electronic offers much sharper timing signal (trailing or leading edge) wise than a round rubbing block lobe