I have 33/43/53 Biospheres up front and 27-11 in back. I just replaced my chain and cassette and they put on exactly what they took off. He counted the cogs in back to make sure the new cassette matched the old one.
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"