Oil filters on a 216 are kind of a waste. If you follow the return hole in the block you will find it goes into the rod oiling galley. This means the filter only has oil flowing through it when the pressure in the rod nozzle galley is lower than the main galley i.e. at an idle.
I think that is why Chev did not install them at the factory.
I have seen 216s where someone has drilled there own return hole, but this can drop the already low oil pressure.
