Back in 2008 Harley changed the 110 valve guides in response to the large number of guide failures on 2007/2008 CVO110's, and they published a Tech Tip concerning the change. In that tech tip they say .596" is the maximum. Click on the attached pdf to read the tech tip. Btw, you should always actually measure these things, not just assume anything Harley or someone else tells you is gospel. I've seen posts by some people on the site claiming they had plenty of clearance beyond the .596" Harley claims is the max, but I have no idea if they left the recommended extra clearance or used that up when they installed a higher lift cam. Harley recommends .080" btw. " Always verify that free travel exceeds maximum valve lift by at least .080 in. "
Jerry