Which distributor to use for HEI swap on '67 327

[jumpsoffrock]

I have read this write-up: http://67-72chevytrucks.com/vboard/s...ad.php?t=13698
I have also spent hours searching google and read countless other threads and write-ups on this subject of converting late 60's SBC's from points to HEI, on every vehicle platform known to man.

I still have one rather important question I have failed to understand though, how can I physically tell which HEI distributors will correctly install and bolt up to my engine--just by looking at it?
Are they all the same and will all work as long as they don't have the "four wire plug"?
Quote from write-up I posted a link to:

Fast68Chevy: any HEi distributor on any chevy V8 without the extra 4 pin flat wiring plug will work, make sure it has the vacuum advance diapragm on it

There is a 1978 Chevy van in a local junkyard with an intact HEI, full setup with Vacuum advance just begging me to scoop it up, but I don't want it if it won't work for me.


Thank you very much.