911SC Engine Serial Number & Model Question

[pitr256]

I have a 911SC 3.0 engine 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 80-81 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 being 39mm according to Bruce and Wayne's books.

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

[boyt911sc]

Peter,

Type 930/10 motors are ROW SC with larger intake runners (-4R) and 39 mm ID. So the intake ports should be the same (39 mm).

Tony

[PeteKz]

As Tony noted, Intakes should be 39mm and exhausts 35mm. Who knows what might have been done to the engine in the past 45 years. Check the head casting numbers. And make sure they are all the same. My RoW heads are: 930.104.329.2R casting K1926d