Help! Rebuilding by 66 dart but im putting in a slant 6 225 bored out to a 227

The stock Mopar ignition system was fine for 1971. Mopar built them fine in 1971.

Today there are design that give better spark energy with fewer parts and equal or better reliability than the original Mopar parts. And today's Chinese built reproduction parts definitely aren't built fine.

The design Chrysler used temps corner cutters to fill the box with sand and cover it with a thin layer of potting. This can work OK if you get everything right. Get a bad spot and get water in there and it's game over, as happened to this voltage regulator:



There are a few better stock replacement options out there but it seems even they get a few complaints.