just drop the pan and get a " deep " filter 6-7 quarts of Dextron 3 fluid dont add anything or funny flushes just drop the pan and replace filter... also when you snap the filter it make sure the Seal that holds it in feels tight or it can suck air and cause troubles... pour in 4 quarts and fire it up and then top it off with it running .. should hold around 6 unless it already low re chevy hot after a part throttle test drive of 2-3 miles