If truly a 55 then it is a 265 with some have no provision for an oil filter mounting boss. 265's for 56 and 57 car and truck had oil filters. 283 started in 57 and had no side mounts that year. You are looking for a cast number like 3703524 or 3720991 for 265 or 3731548 or maybe 3737739 for 283 but your outside the year limit and means replacement.