RockAuto is my goto parts shop, but there are some pretty good deals on Amazon today. To avoid knockoffs I stick to the "AC Delco" storefront on Amazon. Filter by "Prime Day Deals" and you can find a lot of OEM parts for 20% off. I stocked up on an extra ICM, O2 sensor, cap, rotor, plugs, etc just to have around. I find myself hoarding more than usual now-a-days anyway, so may as well hoard at a discount.