I smell oil burning above 3k RPM. Thoughts?

[BrentBTK]

Well, like the title says, I smell oil burning above 3k RPM. It's a brand new Blueprint Crate Engines 350. Seems to run great, I'm about 400 miles into the initial break-in. When I get out on the highway, I notice a distinct oil burning smell when I get above 3k. Below 3k, it's not there at all. My first thought was the oil pressure sender adapter I had to use to clear the intake manifold may drip at very high pressure. I don't see any obvious leaks, but I removed the sender adapter today, re-applied teflon tape to the threads, and took her for a spin. Same thing. I've looked all over with it running and don't see anything obvious. It's lost almost no oil since the initial fill-up, but it is definitely getting pushed out onto something hot at high RPM. Any ideas? Thanks!