Yup, Fine for cast iron heads. The important thing is to keep nipping the bolts up. I check after running for :-
1 minute, 5 mins ,1 mile, 5 miles, 20 miles, 20 miles 20 miles. Depending on gaskets used and heat of engine they may keep moving slightly up to 150 miles, usually around 80. I carry an 8 inch ring with a craftsman 9/16 hex socket in my back pocket when running in a bike and check at LEAST the above intervals. I do it by feel, and testing with a torque wrench after it is around 33-35.