Hmmm, I just posted a reply but it was deleted for some reason. I'm watching Poltergeist right now and I noticed it to, I'm sure it has to be 251, 253 or 256. Judging by the time period and the fact that the top of the cover was dark, I'm not sure, but have a look for yourself:
Amazing story-line, and such great dialogue between the 2 teams. I believe Dr. Strange is going to be laying the hammer down next issue, as powerful as Great Society is, they won't stand a chance against Strange's new ill-fated source of power. EDIT: In fact, I wouldn't be surprised if they get entirely obliterated and we never hear from them again, I hope this isn't the case though, I like them, especially The Norn.