There is a plastic cap covering the threads. I thought it was a bushing .. I'm so dumb
Sorry, my bad. Still need the through the firewall business though. I will cheerfully return the unnecessary bits, of course.
Reading the MSD manual, they say don't mount it upside down because moisture has no place to go. Doug showed me the upside down/under glove box mounting that he uses. What do you think? I am looking at putting it vertically on the cockpit side of the firewall behind the solenoid. Looks like the 4 mounting holes will not interfere with anything on the engine side.
Sam