You're only a few percentage points off (71-75%). You may see a little extra carbonation from remaining sugar in the beer, but I doubt you'll end up with anything terribly out of line.
"Beer, well respected and rightly consumed, can be a gift of God. It is one of his mysteries, which it was his delight to conceal and the glory of kings to search out."
The Search for God and Guinness by Stephen Mansfield