Correct intake rubber sleeves

[ManniB]

Porsche fellows,

I need your help to identify the correct rubber sleeves that connect the intake runners to the air box. My car is an '80 SC with an '81 engine 930/16.

The outer diameter of the intake runners is 39 mm while the ports at the air box measure 45 mm. The original sleeves have the according diameters on each side:



According to the latest PET 7, the order number for the sleeves is 930.110.885.00 which is in line with what our host offers for the model year. I have ordered the parts here in Germany, but what I have received is a sleeve that is 39 mm inner diameter on both ends:



Obviously, the part doesn't fit on the air box side. I didn't try to widen it since 6 mm is quite a long way to go and would probably rip it apart.

Any idea what is going on here? Do I have a non original air box? Any idea about the part number of my old rubber sleeves?

Thanks, Manfred

[ManniB]

Digging deeper into the subject of airboxes (yes, the search function is your friend ;-), I come to the conclusion that the airbox I've got on my engine must be '80 or newer (since it has got the spider/diffusor for the cold start) but for an RoW engine (since it has the larger port size).

Is this conclusion valid?

If yes, is there any negative effect in using it on an '81 US engine and would I benefit from switching back to the correct part?

Regarding the rubber sleeves, can I just buy the ones for the larger port size and tie them down further on the intake runner side?

Thanks, Manfred