BigNick
Thinks s/he gets paid by the post
Well, I'm not an American, so I can't be sure.Is it safe to eat street food for Americans there?

The only things we consumed from actual street vendors were some vegetarian samosas and vada pav, plus some fresh soda/juice combos, plus the ubiquitous masala chai. We reasoned that soda (as opposed to still water) beverages would be guaranteed to be made with bottled water, although of course your typical street food stand isn't plumbed in to the mains water anyway.
We ate in reasonable-to-good quality local restaurants and did not get sick. The only disruption to our digestive systems was the occasional rumble, which in our case was well within the normal range that we encounter when changing cuisines, notably fats (the default fat in India is ghee, which is clarified butter).
Our driver in Delhi recommended against going to a dhaba (greasy spoon), not for safety reasons but because "It's loud and not very comfortable". I would have been up for it, if only to say that I had a meal for a buck, but DW was a bit more cautious. But in Cochin we had a biryani (which we ate with our hands) and two juices in a decent place for $5.