Rode the A64 path between Taddy & York earlier this year, nice smooth surface & better than anticipated, as others have said I would not use A64 beyond York, a bit of a detour but a good route if you have the time is the road through Dalby via Thornton Le Dale, this is a nice approach to Scarborough, as was mentioned up thread from York, A166 towards Stamford Bridge, Buttercrambe, Malton, then Thornton Le Dale, Dalby, Hackness, Scalby, Scarborough.