At the Giro d’ Italia, absolute domination of Ivan Basso on all his rivals.

After the victory in the TTT, Ivan strongly climbed over the Maielletta (940m of difference in height, gradient of 8.4%) in 31’48”, expressing a VAM of 1775m/h.
Paolo Savoldelli, in rather evident respiratory troubles, climbed at 1642 m/h, that is about 8% slower than Ivan.

In the ITT a few days after, Basso rode the flat 50km at an average speed of 50.6 km/h, Savoldelli at 49.9km/h: supposing a similar aerodynamic efficiency, the difference in power output is about 3% in favor to Basso.

On the tough Colle di San Carlo (10.5km at 9.8%) Ivan bettered himself: VAM = 1820m/h, equal to 6.27 w/kg, notwithstanding the rainy conditions and the almost 2000m of altitude.
Paolo lost more than 3 minutes, with a VAM of 1670 m/h (5.75 w/kg), approximately 9% slower than his rival.

Since Savoldelli conceded an additional 5-6% in climbing performance, we can deduce a difference in body weight between the 2 riders of about 4 kg. 
If this is the case, imagining a weight of 67kg for Ivan Basso, his average power output on the climb was 420 watts. Savoldelli, with a weight of 71 kg, pushed 408 watts. 
A difference of 2.9% that would confirm the result we saw in the Time Trial.