I just started my car after a couple years and its doesn't want to idle as good as it used to. I've already drained the gas tank and put 5 gallons of fuel that was stored in a plastic container for 6 months. I performed some maintenance during this period which included all new exhaust and dropping / cleaning the oil pan along with a new oil pump screen. Just to be safe - how do you check the oil pressure in a stock V8?