omar,
1/2 NPT pipe thread on 58-62 261 fittings (only those years; only on 261 engines).
Your lines are most likely 3/8" thread. The oil canister on a 235 was an option. I think that all 216 (37-53), 235 (41-62), and 261 (54-57) blocks came drilled from the factory to allow the addition of a by-pass oil filtration system.
Deve's very clearly described procedure pertains to all high pressure 235s (and 54-57 261s). What year is your block?
Tim
