Don't get Hung Up..............
...........on torque values.............! ! ! ! !
More gaskets are destroyed using torque values rather than the "Common-sensical" approach to seating the gasket with slight compression.
If you're using a typical torque wrench, 0 to 150# or whatever, the values at the low end (0 to 20ish) are nowhere near accurate ! ! , and might be as much as DOUBLE the indicated reading............ESPECIALLY if you're using a "Click" type wrench.
You can get sufficient torque on compressible gaskets using the 'screwdriver-type' socket driver.
..........And, ......as mentioned above, it's an ALUMINUM head, which has to be taken into consideration.
While we're on the subject, ANY gauge, be it for torque, oil pressure, temperature, etc., etc., is most accurate at the mid-point of the gauge...
..very low or very high on the guage reading can be off as much as 20%.....