Personally, I'd deal with 816, 820, 820, 830 by putting 816 in cyl 4 (rear driver side) and the others wherever.
Cut stockers aren't going to get you perfectly matched injectors... It's a cheap way to get ~820cc injectors. There are downsides to that.
You put the lowest flow in #4, as that's what's most closely monitored by the knock sensor and you start tuning with a scalar close to the average of all 4. If you need better than that, you buy aftermarket injectors that are flow matched. You got injectors that are within +/- 1%. That's really not the end of the world.