Vp vibration?

[Hoss24v]

Seems like engine surging. And when I accelerate, I can feel it buck and surge a little more then goes away, then once I'm crushing again it comes back. Anything under 2400rpms, I can feel it. It's factory timing I'm assuming with a hr vp, and a stock turbo

I'll look into that check valve, thanks

I'm sure the trans was rebuilt properly, the person I had rebuild it has a really good rep.