Proper Oil Level for GM 602/604
Questions or Problems contact us at: Ph.: 330-540-7223 or email email@example.com
(all information below is a recommendation from Race-1 not necessarily from GM)
1st) Using the oil level inspection plug make sure you can see that oil is near the hole.
2nd) Reasonably level the engine front to rear and side to side.
3rd) Warm the engine to operating temperature.
4th) With the engine level, warmed up, and running at idle: remove the oil level inspection plug, and measure oil level. (Engines without coolers can be checked with engine shut off.)
We recommend the level to be 1/4 to 3/8 of an inch below the female threads of the inspection hole.
On tracks with extremely long straight-aways, 1/2 additional quart may be needed to maintain a safe level.
Over filling under normal conditions will overheat the oil and cut power significantly.
Engines with oil coolers MUST be checked running.
The inspection plug for the 602 is on the right side of the pan and the 604 is on the left.
Do not confuse the inspection plug with the drain plug as they both have a 9/16 wrench head.