[krellmen]

I have a colt 1911 70series and I want to lower the ejection port. How much do I lower it to keep the brass from getting dinged? I saw a diagram on someones website showing the dementions of a properly lowered ejection port but I didn't copy it and I don't remember the web sites address and I can't find it (web search challenged). Anyway could someone tell me how much to lower the port. Krellmen