How about 5"? Will those fit? Show me a picture of how your stacks mount to the throttle bodies.
These are the stacks for the Webers. They have no mounting flanges. They are held in place by mounting tabs.
http://vwparts.aircooled.net/T...-550-p/52840.550.htm
I found this picture of what you had previously posted.
The 48 IDA is a different mounting method then yours are which are like the Delorto carbs or the Weber IDF series.
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