Hi guys..
I still in process of getting US citizenship so still long way to go.. but I am just monitoring this thread.. I was under impression that US and Indian passports should be sent alongwith the OCI application... is it not true? I see that many people have sent passports much later...
At DC, you can send the Indian Passport and OCI application together. They will cancel your indian pp and approve OCI. Once OCI is approved then only yo send the US passport for U (Oci universal visa) stamping.
hope this helps