Originally Posted by Dave Mayer

Perhaps. However, Campy 8 and Shimano 8 speed spacing is so close, that it is practically interchangeable.

The much bigger compatibility issue is that between the shifters and derailleurs. I have two complete Sachs New Success drivetrains. The shifters are not remotely compatible with Shimano derailleurs and vice-versa. As far as I can tell, the derailleurs are functional copies of Campagnolo 8-speed derailleurs, with an actuation ratio of 1.43:1.

Way different than the 1.67 Shimano actuation ratio.