From the research I've done on here, it seems that most recommend to use a distributor with a vacuum advance. It's been said this helps with efficiency
It will improve efficiency at part and light throttle by better matching the leaner fuel mixes. Less dense mixtures take longer to burn, therefore longer lead helps maximum pressure to arrive at the right time for overall max leverage on the crank.
and not only that but will help me get rid of that big red box on my inner fender.
One thing to note is that the previous owner ripped out the factory electronic ignition wire harness, so it seems that going back to factory will require sourcing out those bits of the factory wire harness.
Based on these goals, and the engine situation, my suggestion is option 2.
Factory distributor with a remote HEI module is a reasonable option. The Chrysler distributor can handle a two stage curve which would be good with an engine like yours. Assuming emissions are not major concern, you can use a shorter but relatively quick first stage and a long slow second stage. (The factory would have been a long but quick primary stage). The HEI module is relatively small (compared to the MSD) and has built in current limiter so ballast resistor is not needed. Of course you could use the 6A, they work fine with any distributor, but that doesn't clean up your fender.
