The engine serial number that HRL asked for is the one that will tell you if it was originally a car or a truck engine.
All car 235s in 1959 originally had hydraulic lifters.
All truck 235s (all years) originally had mechanical lifters.
There are ways of trying to determine a hydraulic lifter without taking the block side cover off - others will advise you on this (I would take the side cover off and look at the lifters).
