Well I gave up on my 320 distributors, I could get it to run one day and the next day it would not even start, I ruined a battery running it down so many times trying to get that damned engine to start, it sometimes would hit maybe once but it would not start.
I did alright with a Pertronix unit modified to fit in the 320 distributor, but after I double clicked and smoked the second unit I gave up on that also(kind of expensive lesson), but it sure started way better.
Then I modified a Matchbox to fit and it started and ran way better, that was just before I pulled the distributor out of that MG Midget engine, but the matchbox will not work positive ground, as the housing is a dedicated ground and cannot be changed, now if my/this 320 had been converted over to negative ground a Matchbox is a great distributor to use as that is what is in my NL320, but my L320 is still positive ground and that is where the Crane ignition system works for me, it has an optical trigger and can be wired for positive ground, and it runs the best it has ever run since I have owned the truck.
I did buy one of them "Accuspark" side entry cap distributors for the other 320 I have as it is RHD and has to have a side entry cap, but I have not installed it yet as that one has started every time so far, well after I put a shitload of time working on that distributor, it's the only one I have left with a stock distributor.
The fact is we cannot get parts for these 320 OEM distributors, we cannot buy new ones either, when ebay has a dist. cap for sale it is over $40.00 plus shipping, I have not seen points or ROTORS for sale publicly since I bought what Tana had(I bought 3 complete tune up kits and I believe I got the last of the rotors) which is the only reason that RHD 320 still has a 320 distributor in it.
These MG/Triumph type distributors are basically the only thing that will keep these 320s on the road unless someone starts making ignition parts for them again.