1991 Chevy Cavalier rocker arm torque

I would appreciate help with adjusting the rocker arms on my 1991 chevy cavalier 2.2 motor. Have found several specs but none are constant as to which one is correct. One is cast iron head you adjust the valve lash. Another is if an aluminum head is present then torque 22 ft/lbs. While another specifies 11-18 ft/lbs. None of which specifies the specific year for my 1991. Just older or newer. I have a 2.2 with an aluminum head so your help would be greatly appreciated. Thankyou