There was a post about this years back. Aren't there also two types of cranks with the same bearing sizes. One is cast the other is forged? Both should be fine providing you get the right one 
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91 Modded 3B
14 A6 Avant Black Edition -
Found the original post
Read post #9Audi 90 quattro (Typ 85)
20v turbo conversion
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Some years ago Roger Galvin and I reshelled an ur-quattro's big ends.
Although we are ABSOLUTELY certain the engine had not been messed with since it left the factory, the big ends were undersize and the shells correspondingly marked.
I haven't trusted a crank since. No matter where it comes from - even if it's out of a box - measure it.Comment
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The old 7A cranks are different but not in measurements...
7A crankshaft is 20kg[__]=oooo=[__]Comment
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