Thanks a lot for everyone's input. I finally developed my underexposed 160VC with 1 stop push. I am completely blown off to discover that this film is not suitable for push processing even by only one stop. The most obvious is that the shadow basically has nothing but deep black there. It makes my images way too contrasty. Besides, the colors are off a bit too. This may be the effect of being too contrasty. The images are still usable although they are difficult to scan now. By looking at the histogram the underexposure (by 1 stop) effect is clearly visible. I have to conclude that 160VC better not not be pushed. This may apply to most if not all negative films too. I will probably shoot this film next time with ISO 100 set in my camera.

I developed this underexposed 160VC 220 with 850 ml Kodak C-41 developer for 3 minutes 45 seconds. Judging from the result I don't believe longer development time would have made it better. I will find out how to post a sample image next.