What screw on cassette block do I need for a 1990 Campagnolo rear mech?

[silvermuse]

Hi, I have an old road bike with a full campagnolo chorus group apart from the 6 speed Shimano screw on block cassette. The problem is the rear mech keeps goes in to the spokes. I've adjusted it as much as I can with the rear mech screws but it still does the same, Does this happen because the gear levers aren't index? or because the block needs to be more speed? or something else? Many Thanks

 

[Aperitif]

http://www.parktool.com/repair/readhowto.asp?id=64 might be a good starting point.

Welcome. Further investigation might lead you to the 'Know How' section - you would have had 20 answers by now silvermuse.