See eBay item 112308690194 engine bore ridge reamer for sale I have used it once does the job well. I was going to re-ring
And did not want new ring contacting top ridge. Not common here in U.K. See Utube for demo very useful tool.
PM if interested. Colin shaw
eBay ridge reamer
Re: eBay ridge reamer
Link http://www.ebay.co.uk/itm/ENGINE-CYLIND ... SwTuJYqbdU" onclick="window.open(this.href);return false;