Vibration right off idle

Has this engine ever run before? Or is this a 100% new build?

All the trans recommendations make sense, but don't forget the basics. Verify your firing order? We all screw it up at least once and it can cause some odd issues with the right cyls switched.

The engine, while relatively new has been run with the 904 behind it for a very short time. This can't be. Misfire. I can feel it in my seat.