Valve cover bolts - 8.9 N-m, 6.6 lbf-ft, 70-85 in-lb.
Please use something like a 1/4" drive in-lb torque wrench. Slowly in steps using criss-cross pattern when tightening.
Doing 6.6 ft-lb with a larger wrench will most likely strip this small fastener.
If gentle hand-snug is leaking then most likely gasket has slipped during installation, is cut and/or needs replacing, or one or more fasteners are stripped.
Stig