I decided to replace my MSD coil, #8222 as it was out of spec, though not horribly. It was 5+ years old so it held up well. I went to OReilley, Autozone, Hawaii Racing, and found that the same coil, all 7 of them, were all out of spec as written on the box and stated on the Holley website, 4.5k for the secondary resistance. Secondary resistance is red lead on positive post and neg lead on coil wire tower, 20K setting on multimeter. Primary resistance is red lead on positive and black lead on negative 200 setting on meter. I checked them all out of the box and got readings of 6.0 and up. Called Holley tech support and they agreed 6.0 was reason to reject the coil, and they verified it should be 4.5k up to 5.5. I asked if they could verify a good coil then I would order from them but they said No, as did Summit and Jegs. So.. I got the red MSD Blaster 2 #8202 which did have the correct specs from PepBoys, and is the same output. It has to mount vertically, so they say. Smoother idle and a steady tach.
Anyway, point is to check the specs on electronics if possible, as they might be out, even when new.
By the way, for those with points the MSD coil 8203 has a resistor that comes with it to allow it to work correctly.
www.holley.com
Linda
Sadly-Linda has passed away 2022. She was the 311's den mother and drove the first Rare-Parts ball joint project. RIP.