Regardless of whether the head was sent to an automotive machine shop for valve servicing, ensure it is clean before beginning reassembly. If the head was sent out for valve servicing, the valves and related components will already be in place, so start the reassembly procedure accordingly. Install new seals on each of the valve guides, noting that intake and exhaust valves require different seals, so do not mix them up. Gently tap each intake valve seal into place until it is seated on the guide, using a deep socket and hammer; the intake seals are light brown and the exhaust seals are gray. Beginning at one end of the head, lubricate and install the first valve, applying moly-base grease or clean engine oil to the valve stem. Drop the spring seat or shim(s) over the valve guide and set the valve spring and retainer in place. Compress the springs with a valve spring compressor and carefully install the keepers in the upper groove, then slowly release the compressor, ensuring the keepers seat properly. If necessary, apply a small dab of grease to each keeper to hold it in place, as the small valve stem keepers are easier to position when coated with grease. Repeat the procedure for the remaining valves, ensuring to return the components to their original locations without mixing them up. Finally, check the valve spring installed height with a dial or vernier caliper.