My car is at the 165,000 mile mark, had the headgasket redone with a MHG Bead style @ 155,000 and have been using dino oil 10w30 since. The bottom end was left alone when the head was done and i don't know if its ever been touched. I change my oil every 2k miles with a new toyota filter, but after reading that oil filter post i think im going to switch to napa gold. But my question is can it hurt anything just switching directly to synthetic? Should i use a blend for a oil change or two so i dont shock any bearings? Or should i just stick with dino oil...