Recommended Oil Level for GM 602/604

 Questions or Problems contact us at: Ph.: 330-540-7223 or email brad@race-1.com

(all information below is a recommendation from Race-1 not necessarily from GM)


  • First, reasonably level the engine front to rear and side to side.
  • Second, using the oil level inspection plug make sure that oil is near the recommended level.
  • Third, warm the engine to near operating temperature.
  • Finally, with the engine level, warmed up, and running at idle remove the oil inspection plug and measure the oil level.
  • NOTE: If the engine does NOT have a cooler, shut it off to check the level

We recommend the level to be 1/4 to 3/8 of an inch below the female threads of the inspection hole.

GM calls for 8 quarts with filter.

MOST WILL BE OVERFULL with 8 quarts. (non-cooler engines)

Install 7 quarts, and check as described. Add as needed.

Over-filling under normal conditions will overheat the oil and cut power significantly.

Engines with oil coolers MUST be checked while running and WILL require more oil.

Engines without oil coolers do not need to be running to check oil level.

The inspection plug for the 604 is on the left side of the pan while the 602 inspection plug is on the right side. Inspection plugs are in the middle between top and bottom. DO NOT confuse the inspection plug with the drain plug that is located on the right rear extreme bottom of both pans.

Both inspection and drain plugs will have a 9/16 hex head.

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