Engine number and casting number are two different things... The casting number Z129A600 is the same for all TO-30s... The engine number (EN) is on a plate rivited to the engine near the coil... Z129-xxxxxx with the x's in the range 300,000 to 380,000. The tractor serial number (SN) is on the plate under the steering wheel and is TO-yyyyyy with th y's in the range of 60,001 to 140,000.
My correlation is between TO serial number (SN) and Engine Number (EN). Data that doesn't have both of these number (EN, and SN) was eliminated from my list.
Jim in OH