I'm running a stocker Duraspark base in my 351C door car - breaker plate locked, MSD pickup, big cap/rotor. No mods to the body, 6500~7000 for years now. Timing perfect, big moly pump drive and no issues with that either. I run a crank trigger on the dragster - if the MSD distributor on that died, I'd yank the home made unit out of the door car in an instant and not think about it. I keep a drilled old Ford big cap that I use to set the rotor index with the crank trigger. I run a similar unit on the 302 using a small AMC 304 cap to clear the tunnel ram, been running that one for several years. You built an FE that can run to 7700 but you'd like to cheap out when it comes to the distributor? If you're worried about 50 year old units, spend the $ on a new unit or do the extra fab and hoop jumping to run the belt drive.