ok so im pretty new to carb fed engines, i have a 454 bored over 30 with maybe 1000 miles on her, earlier today she was running great, i just went to the grocery store and right off the bat it wasnt really building oil pressure, i had to hold the gas pedal all the way down for a second just top get it started and it sounded really rough and would lose oil pressure and die if i let off the gas at all, then while driving up the road it sounded kinda like a tapping noise, not like a rod knock just a real slight tapping, im thinkin the oil pump or the head gaskets but like i said im new to carb engines any and all help would be greatly appreciated