Difference in cylinder head part #s?

[dnalbach]

I am wondering what the difference is between the following two parts #s for cylinder heads. Both are manufactured in 2001 and are supposed to be the shared 3100/3400 head.

24507487-237
24507487-232

[SappySE107]

Only difference possible would be the AIR injection in the exhaust ports. Otherwise, they are identical castings.

[3400-95-Modified]

I'm sure the 237 and 232 stands for the fixture used to make the cast to make the head. For some manufacturing if there is a fixture reused they will label it with a number so if multiple parts show up out of spec and all have the same cast number on them they know which fixture is wearing out and can eliminate it from circulation.

[dnalbach]

Thanks, that's good info