Fir H1B with Same employer but different client and location - is Amendment required before stamping?

I have an approved H1B until 2019 with Employer X for Client A, Location 1. I have my stamping interview scheduled for next week for the same employer but for Client B and Location 2.

I have a new LCA for Client B and Location 2 but have not filed the Amendment.

I don’t have the client Letter but I have Statement of work (SOW)… Please advice as I’m worried of getting any queries…