Here's the bugaboo. All accounts I have read say the YB35 and YB49 variants were scrapped long before i (repeatedly) saw them (or a plane that looked a lot like them) flying out of Andrews AFB when I was a kid in the early '60s. I recall they left soot trails in the air, too, (much like the F-4, only multiple engines), so I'm betting on jet engines.
So someone isn't telling the whole story.