MSD, can you tell the difference?

I have several MSD units. On the street, the 6 series can improve both mileage and driveability. I have swapped between a Pertronix and the 6a on the same vehicle with very obvious results. Because the Pertronix is the trigger for the MSD it is a quick swap for comparison.

The high output allows you to make changes that other ignitions simply will not deal with. Bigger gaps make for a longer spark, and better exposure to the fuel / air charge.

You can run a much colder plug - like an N19V Champion. A point ignition may not even fire that plug.

I have never had one of my own MSD's fail, but I do know what will kill one. A friend of mine went through 3 of them in a month - he was pretty angry about it.
I stopped by to help, and he was fighting a miss with a point distributor. He had the can type 8203 MSD coil on it. I pulled a plug wire, and there it was - "Snap Snap Snap". Coming from the coil. A crack in the tower, and it was firing to the negative terminal on the coil - from just below the boot. I still have the coil, most people can't see the crack before I point it out.

Two years later, someone else asks me about the MSD, and wants to know how many I have killed. "None". I asked to see his install. OEM ford coil, with a visible arc track across the coil. Same story, starts missing at WOT, just suddenly quits for good. MSD charges 100 bucks to fix it.

I use the MSD 8207 Blaster coil on street cars. No way to zap the primary side from the tower. Never had a failure with that coil. My work truck has close to 100k on the 6a & that coil. I gap the plugs at .045 - and run them 30 k miles.

B.