Thanks for sending the model number of the tractor. I am sorry we asked for that, but it is always good to know.
The valve clearance on your Briggs and Stratton model 446677-0463 is .004-.006 on the intake and exhaust valves.
The torque for the head bolts is 220 inch lbs. Torque on the rocker arm nut is 60 inch lbs.
If you need any other torques or information, reply on this thread and I will be glad to help.