Those have a Mallory YH type advance mechanism. Very difficult to get a really good curve in them due to the design.
Rick's at least is essentially a Chrysler type advance. I've only had one person measure and share timing curves from one of Rick's distributors, but at least the adance curve will be ballpark correct for your 383. 2 bbl and 4 bbl should have difference advance curves. A search should turn up previous discussions about what the these look like. Getting the timing about right is more important that creating fireball sparks..