For moving these an exact amount, I would use the "nudge" command. 
 
If you go to preferences > customization > nudge
 
you can set the exact amount of time you want the nudge command to be. You can set it with ticks, milliseconds, or whatever. 
 
Once you set it to what you like, you can select multiple clips, or even do them one at a time, and nudge them with the process > nudge command. 
 
gabo