911SC Engine Serial Number & Model Question Options

[Peeterabytes]

I have a 911SC 3.0 engine on my 914/6 and trying to determine correct intake manifold size for new 40 PMOs. The stamp for the engine model type is 930/10 which led me to believe it was an 80-83 RoW model. Which means the intake port should be 34mm. However when I measure the intake port it's 39mm.

So when I check the engine serial number, 6382839, according to some prior posts here the third digit means it was built in 1978. And that corresponds to the intake port corresponding to the 39mm listed in Bruce and Wayne's books for 1978 RoW 911SC engine.

I think I'll go with what I measured but I find it very odd.

Any of you experts have an idea of what is going on with this mismatch between the type and serial number?

Thanks,

Peter