If you are fortunate enough to own a second-generation GTO you have a truly beautiful ride. Your GTO is all muscle, whether you have the 400-cubic-inch V-8 or the high-output, HO 455 found in "The Judge" models. You will want to keep your engine running strong and well lubricated, so putting in the proper amount of oil is key when performing an oil change.
Oil Capacity for 1970 GTO
The oil capacity for both the 400 and 455 engines is 5 quarts with a new oil filter installed and 4 quarts if filling the engine only, with no new filter.