Hello this is my first post. I have been following this topic for a while so wanted to add my views.
The main road is actually still Stockport Road, Dan bank is a small cul-de-sac at the top of the hill.
I think you will find that Stockport Rd/Dan Bank was called Dan Bank long before the cul de sac and the houses thereon where thought of. The (c18thcentury?) farm overlooking the road is called Higher Dan Bank Farm which suggests that there may have been another, similarly named farm in the vicinity.
The houses on the cul-de-sac were built in my father's lifetime. (He came to Marple as a six year old so was a new-comer, as a friend informed him shortly before he died, aged nearly 80!). He told me that the main road was called Dan Bank long before he came to the village (as it was then). It is more likely that the cul-de-sac was called Dan Bank after the main road as a convenient name, rather than the main road being named after the cul-de-sac.