Being from the late 1960's there are quite a few things that make this engine stand out. This aluminum block engine utilized an over head cam (OHC) design. Two timing chains are used. The crankshaft drives an idler shaft and the idler shaft drives the camshafts. The cylinders are removable with only an o-ring at the bottom to seal it to the block. Head gasket fitment and thickness is critical to ensure that there are no coolant leaks internal or external. You also may notice that there is no provision on the block for a mechanical fuel pump as this used an electric fuel pump.