It would have to be 4th tier only, though even then that would surprise me at W6 D2 L1, it's a great start but not Earth shattering. Then again we'd only be going back to 1987 as nobody was promoted to tier 4 before that, only the odd team elected.
In the Football League as a whole, I hate to say it, but you don't have to look very far from Notts for a team that had a better 9 game start following a promotion and I expect there are numerous other examples.