Cylinder head casting

[YM1720D]

For you all that have head the valve cover off I have a question.
I was checking my valve clearance yesterday on my 1720 and cast into the head was 3t72. It was between to sets of valves. The tag on my valve cover says 3t75. I was a little thrown off by that and am now wondering if that is normal? Maybe 3t72 and 3t75 heads interchange? Or maybe it means nothing and I'm paroniod :laughing:
Anyone else seen the engine model cast into the head?

 

[YM1720D]

I went back outside and checked and I do have 3t75 stamped on my block. I was hoping I didn't have the wrong motor in my tractor lol. Is it possible I have the wrong head on my engine?

 

[Neat 1500]

apparently thats common, some model engines have shared heads between them. nothing to worry about.

 

[Coldwater]

was your tractor a Vietnam recon tractor???

 

[YM1720D]

No not a Vn. I wrote Aaron at hoye and he said that Yanmar does that from the factory and casting numbers rarely march. Some even have John Deere casting numbers. So nothing to worry about. I knew I was being paranoid for nothing lol good info to know

 

[Car Doc]

fwtw my engine casting is different than my cyl head also and I wondered the same thing and ended up finding out it was correct.