Well sure, I think it goes without saying that anything done on a dyno won't necessarily reflect the same in a car but it still shows similar trends. What did you find in your testing that was different than the Engine Masters results?
I personally end up going to multi-spark setup (not MSD brand if I can help it, I don't trust their quality and value isn't great) with electronic distributor in my classic Mopars anyway because it eliminates the ignition system as being a potential source of issues. I have a Summit brand billet distributor with vacuum advance in the "medium" built (~450 HP) 360 in my Duster because it's so much easier to precisely adjust and tune compared to a factory one and I'm about to put one in the mostly-stock 360 in my D200 pickup. The process of modifying the mechanical advance plate in a factory distributor with epoxy or welding is just a time-consuming pain in the butt to me. Not to mention ballast resistors are also annoying and pointless in this day and age IMO.
FWIW I bought a Mallory HyFire-6A box back in 2008 before they were bought out by Holley/MSD and it's been working like a champ ever since. If you can find one of those older Mallory boxes I highly recommend them. I think I already mentioned the Pertronix Digital HP box, that's what I have in my truck and it's been great, only had it for a couple years though so can't speak for its long-term durability.
