Make sure you run a tap through all the holes in the block, wire brush the threads on the head bolts. Make sure your liner height is correct and the head is flat. I would use some 3M-EC847  and put a fine bead of it on the pushrod side of the block  top and bottom side of the gasket to keep oil from seaping through. Use at least 4 steps to torque the head, Start in the middle and work out. Torque it to the minimum torque value. Once you have the tractor runable run it for a half hour to warm it up. Then torque it to the maximum value and reset the valves. Going by memory toque is 112-117 foot pounds except for the hollow oil bolt which is 100 pounds. More questions?