66K Is it too late to go full synthetic?

mike444

So im also looking to flush out and replace most of the fluids, I'm ordering:

- break pads(Front & Rear)
- Valvoline DOT 3 and 4 Synthetic Brake Fluid (32oz)
-5 qt full synthetic of mobil 1 or pennzoil platinum

Getting these from Thenismoshop.com, are the reputable?
- OEM tranny fluid (2 qt's)
- OEM Nissan drain washers( I need 3 Right, 2 for the tranny, 1 for oil)

Is changing the spark plugs a good idea?edit: just read there good for 100k
Should I also get the OEM power steering fluid, and how much of do I need? Also when changing the Motor oil do I need a new plug or is the same one ok?

Pretty much trying to do a full service, Thanks for all the input.