Back in the day, there was a difference between how Google responded to a 404 vs a 410 server header response code. 410s were faster and more permanent.
It seems as if that may have recently changed.
A Google Webmaster Help thread has Googler John Mueller giving us an update on the differences, or lack there of, between the 404 and 410.
He said, “even back when we differentiated between the two, the practical difference was just a very short time-difference, the overall process was the same.”
To be honest, it isn’t 100% clear if Google stopped differentiating between the two but it seems they have.
Why have they? I assume because most sites probably don’t bother 410ing and just 404, at best.
Forum discussion at Google Webmaster Help.
Update: John Mueller got back to me to say he was wrong about this, he told me:
