Headlight Cleaning Guru
Join Date: Jul 2002
Location: H-town, TX
like steve said, spray some degreaser on there (oil pan, oil pump, rear main area, drain plug, timing cover) and scrub it clean. it may help to hose down the underside with a pressure washer. change the oil while you are it. go over and check to see if any bolts are loose. you must locate that leak.
if you choose to do a 5.0 swap, i have many stock parts to help you get started.
1990 300ZX TT