I tried this recently, my canti's would not work without moving the bosses. I sent an email to captainbike and he confirmed that it likely would not work. Ther eare still good 27 inch wheels out there. BTW if your clearances are tight its doubtful that you have an actual touring frame, you probably have a "sport touring" frame.
In any case test fit it first with a loaner wheel if you can.
D