Arrange the parts in the same orientation they had on the motor when assembled so they go back the same way.

Remove pushrods. Inspect both ends of each pushrod. The ends must be smooth with no signs of damage or wear. Roll the pushrod on a flat surface (e.g., plate glass) to check for signs of bending. Some say all four are identical and interchangeable, but others say to reinstall them in the same position and with the same orientation upon reassembly. The latter is the more conservative course, and recommended.