When replacing the oil pump on a 97 Buick 3800 supercharged engine what gaskets and seals are needed?

Oil pan gasket and pump gasket. Be sure and clean the oil pan out throughly and clean the strainer. If you find the oil pan bolt holes are protruding inward, then with a small hammer, make sure to flatten then out to ensure a good seal. Tighten all bolts to OEM factory specifications, to avoid leaks.