I'm rebuilding a 1950 Black Shadow and recently bought some oversize cylinder liners from Coventry and took them to my machinist to do the key cut and drill the oil hole, etc, and took him an old liner to show how it is done. He brought to my attention that the undercut at the lower aspect of the liner was smaller than my old one so I brought the new ones home and slid them in the crankcase holes to check them . They were easily rocked back and forth in the mouths and using feeler gauges, I was able to measure 10/1000 inch gap. I'm a pack rat, so I found some old liners from my first project, Rapide 697, and was able to appreciate a gap of 5/1000 inch. I spoke with Bill Parr, technical director and he felt that .003-.005 was the upper acceptable limit for clearance. I bought some new liners from the Club and they seem even looser. I've found a firm in the US (where I live) that will do reverse engineering from a sleeve to create a new sleeve, and I'm considering sending them one of my new sleeves and just asking them to reproduce the sleeve with less undercut at the lower aspect but this seems like a big deal. Are the vendors making them smaller so everyone can "get theirs in" thereby creating difficulty for those who have slightly bigger crankcase holes? Any comments regarding similar experiences or use of other vendors or sources for the sleeves will be greatly appreciated. Thanks, Charles Cannon