Yes it's perfectly fine, You won't notice a difference. The name "synthetic blend" is a bit misleading, as you're not really getting anything close to a synthetic.

 

Vortec bowtie, Check out my input on the thread which you started elsewhere. Seal conditioner is basically stop leak by a different name. Swells seals! temporary fix to leaks at best. Causes more leaks down the road if you go back to non high mileage oil. Also, Thicker oil effects fuel economy.