I've been running MSD boxes in most of my cars for the last 10 years without any issues. I do keep an extra MSD-6 on hand just in case I have a failure. Maybe it would be most convenient to get yourself a second one if you're committed to an MSD. They show up at swap meets all the time and are usually cheap. Two of the ones I bought were used and both worked great. I know buying used is a crapshoot but if you find one from someone you trust you're likely to be OK.
