I got a PM asking about swapping a carbed 4.3 in their G-Body, just thought I'd share what I found.
Looks like the best source for a distributor for a non-computer setup will be a full size truck, Astro van, or full size van with a 4.3. My search brought up both ECM-controlled and vacuum advance distributors, so make sure you're getting the right one. The cap looks just like a standard SBC cap with coil-in-cap. Also, the distributor body may actually be the same as an SBC since it shares so many dimensions with a 4.3, but the pickup coil is different, so even if it is a drop-in thing, it won't run due to the different pickup coil.
Cap
Distributor
This is the one you
don't want, as it's controlled by the computer.