One set of primaries on a single 390 doesn't seem to keep the engine afloat; at least, not with the tunnel ram. It idles for about ten seconds and then sputters and dies. I tried running it on one 390 when I needed parts for the other; figured I'd just block off one hole and the related vacuum / fuel lines and run to Schmuck's on one carb, right? Not.

I planned on someday trying to run the carbs progressively until I tried to run on just one.