I run the original 284/484 purple cam in my numbers matching 383 magnum

Idles perfectly at 700 rpm s all day long , starts and runs cold at idle even without a choke plate in my factory carter avs carb

16 degrees initial at idle

20 degrees mechanical advance all in by 2400 rpms

I replaced the slotted t bar within the distributor , taken out of a slant six to shorten the slots for mechanical advance

36 degrees total - No vacuum advance hooked up even though it looks hooked up at carb