Casting numbers are NOT part numbers
A casting can be machined differently an used in various assemblies which get you to different parts (and part numbers)
Example:
head casting 3835499
head casting 3835499 is used in part # 3835545 for a 235 engine 50-53 in USA, these are likely babbitt 235s
head casting 3835499 is used in part # xxxxxxx also found on Canadian 216 51 engines (block 3695408)
head casting 3835499 is used in part # 3703569 for a USA 54 261 engine
