These are usually stamped into the cylinder block on a flat machined surface, often just above the oil filler tube. Note that engine numbers may not always match the tractor’s chassis serial number. International Harvester Serial Number Table
The physical location of the serial number plate depends on the specific IH model series: International Harvester Tractor Serial Number Table-
The following table provides starting serial numbers for select popular IH models. These numbers represent the first tractor produced for that specific year. Yesterday's Tractors IH Tractors - identifying model from serial number These are usually stamped into the cylinder block
Typically located on the transmission housing or seat support. International Harvester Tractor Serial Number Table-