I have kept the original factory spark plugs and the numbered set of spark plug wires that were delivered from my RL411 [in a special place, not in the car]. BTW I have kept all the original parts that I have replaced all these years just in case I might want to duplicate the as factory delivered car. No! I did not keep the original oil filter or the drained oil! But I have the original distributor cap and rotor. The engine mounts were replaced many years ago when they were still available. The only major deviation is that I replaced the oil pan drain fitting with a Toyota 18 mm plug and retapped the cast aluminum oil pan with a Ford 18mm spark plug insert. Why? Because I stripped the odd ball helicoil insert when doing an oil change, It's a "semi finished SAE thread" which guarantees that Helicoil will kiss you goodby! Only a Ford insert will fit! All other 18mm replacement insets are tapered seats, the Ford insert has a flat surface and mates up with the Toyota plug exactly! Of course you need 18mm plug seals to keep your driveway clean! But the sight of an antique DATSUN driving to to our local Toyota parts window will certainly draw the attention of the dealer's mechanics.