The nonaircon 20v uses Magneti Marelli A115I type alternator. If the 1.6 is older, it might have the same alternator, or if it is newer, it might have a bosch unit.
I'd say if the mountings fit and pulley can be changed/is same go ahead and try it. The electrical connections are same on all B/B/M (ground on frame, supply and idiotlight/excitor).