Different oil filter canisters fill and drain differently. Assuming you have an AC filter: where does the hose from the bottom of the canister enter the block and where does the hose higher up on the side of the canister enter the block?

Here are the inlet and outlet holes on the 235 block. Hose to inlet is on the upper side of the canister and the outlet hole is on the bottom of the canister.

Here is a diagram of AC oil filter plumbing compliments of Denny Graham.