http://www.ebay.com/itm/Weber-Carburetor-46IDA3C1-46-IDA-/120872303109This is for
4 NOS 46IDA3c as fitted on the Lamborghini Miura and the early Porsche 911
This is not to be confused with the 46IDA 2 barrel downdraft as fitted on the Porsche 904 GTS
Finding the 46IDA 2 barrel is nearly impossible since it was a race only carburetor and the production was very small. Some parts from the 48IDA are interchangeable with the 46IDA but none are interchangeable with the 46IDA3c
This seller is Pierce Manifolds out in California. Extremely knowledgeable Weber experts
good luck in your search