It's funny because the first time I took that measurement, it was because someone was asking about it. The only concern I had making that hole was for it to be well centered in the shaft. For the rest, I just went by eye and tried to match the location of the hole in the Losi output cups
0.190'' is fine and don't worry too much about it, worry more on making your holes centered on the shaft so that once the pin is in the hole, the shaft slides in the gear without too much force.