Congratulations cliffcarey68, that's an excellent score! I have only seen a few pictures of these engines and have also sturdy'ed all their specs I also know that it was Ford's practice to use many of the same parts for their many different engine sizes both here in the USA as well as in other countries. So there should be quite a bit of parts interchangeability between the 221 and the US 200 & 250 engines a few of the parts like the Piston Rings since they share the same size Bore For all 3 engines. The Rod and Main Bearings likely might be like those used on the 250's. From what I have learned the 221 block uses the wider camshaft spacing that was used on the US 250 Six short blocks. This would mean that the Timing Chain / Gear set should fit, there are 4 versions of these with the 1969 to 1972 being the best of the lot. Probably the 250 Oil Pump will also fit, all the 250 Gaskets for the Short block and most the others as well as the Head Gasket should fit, the Intake Gasket though will be a 221 only item. The Pistons could be a 200 or 250 Compression Height so that will need to be measured. The 221 Crankshaft Stroke is a one of a kind but if you wanted to use a 250 Crank for more stroke might be able to fit no idea which Connecting Rod or Piston would be needed but likely it would need to be a custom made one to fit into their shorter deck height of the block. Valves, Rocker Arms, Distributors, and Valve Covers should interchange. The Intake Manifolds are one of a kind, I don't know if the Exhaust Manifolds / Headers will interchange I suspect that they will. Would you take some good pictures of your 221? Best of luck on your 221 Six rebuild.